Pistache for posterity

A 94-year-old lady came in today and bought our largest Chinese pistache to plant in her front yard.
 I was raised that you don’t mention a lady’s age. But she volunteered it, and I think at a certain point that old rule doesn’t apply.
I’ve known her for a long time. She isn’t getting around as well as she used to, so her sister drove her in. Her sister lives in Texas, but comes out to visit and help out now and then. She’s 91.
 The old walnut tree in their front yard died, so it had to be taken out.
 “We weren’t going to replace it,” said the sister. “At our age, we’d never see it grow. But,” she paused.
“You should plant trees no matter what your age,” I replied.
“Yes, you should,” she agreed firmly. “Plus, our doctor lives across the street, and he said he wanted us to plant a tree.”
“You do what your doctor tells you,” said the older sister with a smile.
So, doctor’s orders, she bought the largest tree we had and arranged for a young man to come out and plant it.


 The city had planted one Chinese pistache already in their front yard a while back when the Modesto ash came out. That one is a female tree, doesn’t color up so well. “The females do have pretty berries,” I said. “And the songbirds enjoy them, even if they are a bit of a mess.” But they especially wanted the fall color. 

The reason we sell the grafted Keith Davey Chinese pistache is for that reliable fall color and the fact that it doesn’t have the berries. Most people prefer that; they want to know they’ll get that familiar bright red color. And while the pistache berries aren’t squishy, there sure can be a lot of them. Pistacia chinensis is dioecious, having separate male and female trees. With nursery stock grown from seed, you have a 50-50 chance. And the fall color ranges from yellow to orange to purplish to red.

I’m partial to all of them. I live along the freeway, where CalTrans has planted mixed seedlings. And Chinese pistache is fecund enough that more seedlings have augmented that stand. I bought a tray of seedlings from a grower years ago, culled out those that lacked good fall color, and planted half a dozen of the best on my property. I have some male and some female. Lots of winter songbirds enjoy the female trees. But I understand why homeowners want to know what they’re getting. For reliable fall color, plant Keith Davey.

Chinese pistache is one of our most common landscape trees. It can tolerate drought (many of the trees on or adjacent to my property get zero summer irrigation). It can also tolerate reasonable lawn watering. No pests and few diseases. A small percentage of trees in some parts of town die from a vascular disease that looks and spreads like verticillium wilt. The pathogen hasn’t been confirmed, but if you do lose one I suggest avoiding trees that are known to be susceptible to that when you replace it. But thousands of them grow without incident around the Sacramento Valley.

 The growth rate is what we call moderate. Watered deeply, fertilized a bit when young, they grow two to three feet a year up and out. In ten years you have a nice medium tree with equal spread to height. In a couple of decades, you have a good-sized tree. Eventually they can get quite large. Roots are deep. A little gawky when young, they barely require pruning once established.

This is the tree that has the most reliable, consistent fall color in our area, beginning in late October and continuing through November. When they turn color varies with watering regimen, exposure to cold, soil nutrition, and other factors. Unirrigated trees, such as those along the highways, turn color first. And even with the right genetic material, some trees don’t give good color some years. A tree in a sheltered courtyard may disappoint you, and some years are better than others. Nature is fickle.

 But if you want fall color, this species is your best choice here. And in the right year, the right place, the right tree, the results are spectacular.

 I like their attitude. Yep, they can grow that. And you can too.

Rethinking Lawns

Lower Water Lawn Options

written for the Davis Enterprise, July 26 2012

As Davis faces water rate increases, garden professionals get lots of questions about ways to conserve water in new and existing landscapes. Previous columns have discussed low-water options for shrubs, ground covers, and trees in the landscape. The biggest water-user of all is the lawn. But that presents a conundrum, because the lawn is part of the yard we really use. Someone moving to a new house was asking about options and noted, “I have a big conflict about water usage. But we have two small kids who play on grass. Tough to play on cacti beds!”

Let’s not disparage lawns too much. That water use does provide natural air conditioning, heat reduction, and reduces dust. A normal lawn watered optimally requires about a thousand gallons of water a week per thousand square feet. But it takes that water and pumps it back up into the air around your yard, providing evaporative cooling. Grass is much cooler to walk on and work around than are bark, decomposed granite, concrete, and other non-plant surfaces. In California we use our yards as extensions of our living areas, and there is no question that a lawn is a more comfortable place to be than a drier landscape. Dogs and kids like to play on them.

As noted in my October column: "Form follows function," Louis Sullivan said. Let your landscape form follow the actual use patterns of your family. Lawns are for kids and dogs, and are usually unneeded in front. Put lawn where you will use it, not just where you'll look at it. Reducing your total lawn area is a simple way to save water.

You can probably reduce your total water usage on your existing lawn. Lawns don’t need daily water. A rule of thumb for traditional lawns is one inch of water, two times a week. Measure to see how long your sprinkler takes to put out an inch of water. I find most people aren’t watering long enough, but are watering way too often.

You could get a “smart timer.” Once the realm of commercial turf areas such as golf courses, these have become less expensive and may be appropriate for those of you with large lawns.

These amazing lawn sprinkler timers communicate with local weather data sites to determine the rate of watering needed, and adjust accordingly. When weather is cooler than average, they reduce the output. You can do the same thing, of course, but it takes some awareness of actual water use rates. The IPM web site maintained by UC Davis has links to weather stations all over the state, providing ET data (ET = evapotranspiration, the rate at which plants use water. It is measured in inches, just as rainfall is. Lawns use up to two inches of water a week in our hot, dry climate).

Go to http://ipm.ucdavis.edu/WEATHER/index.html and find the local weather station. Add up the ET rates and provide the water use calculated for the previous week.

Or you can be intuitive: if it’s cooler than average for the time of year, cut how long your sprinklers run a bit. We tend to fluctuate between short intervals of high temperatures, and periods when the delta breeze prevails and cools us off.

Keep an eye on your lawn. If it is looking duller green than usual, it is probably water stressed. Poke a trowel into the soil and assess the moisture. Water rates we give are optimal. Perhaps we can all learn to accept a little turf stress as long as the overall appearance is good enough.

If that all seems too complicated, the smart timers may be worth the investment. Local irrigation supply companies can give you more details, and a landscape contractor can install one for you.

Second option is to change your type of grass. All grasses are not equal in their water use. Until the advent of tall and dwarf fescues, most lawns were blends of bluegrass and perennial ryegrass. Those are the highest water users, and tend to be more susceptible to diseases. If you’re in an older neighborhood, it is possible you still have a blue/rye blend.

The newer, coarser-bladed fescues (tall and dwarf) can get by with as little as 20% less water than those older grasses. They are deeper-rooted, so they can go longer intervals between waterings.

If you have an older lawn, simply converting your lawn to a tall or dwarf fescue would enable you to cut your water use immediately. But they have a less refined look and require taller mowing height (preferably about 3 inches height in summer). If you are in a neighborhood built from the early 1990’s on, your lawn is probably already one of these blends of “dwarf tall fescue.” Yes, I know it’s an oxymoron: “dwarf fescues” are the lower, slower-growing strains of tall fescue.

Fescue is an important group of grasses. Most lawn blends that are labeled for shade contain another type: the fine fescues. The two most common are creeping red fescue and chewings fescues. They happen to tolerate more shade than other grasses, including the dwarf and tall fescue cousins. But we should all be using these more, as they are tolerant of even less water. Data I have seen show fine fescues can use up to 20% less water than the dwarf/tall fescues. They grow in full sun just as well as in shade, and make a very attractive lawn. As with other fescues, it is very important to mow them high (the grass, not you). Fescues have a high growing point. If you cut them too short, especially in hot weather, a lot of the individual plants will die out and the lawn may thin out. Mow at three inches if possible.

So converting your existing lawn to fine fescue can enable you to use 20 to 40% less water overall. If you don’t mind the appearance of grasses of differing texture, you can just over-seed your lawn and let the fine fescues fill in around your present grass mix. Otherwise, you can kill your lawn with chemicals or black plastic first. Fall is an excellent time to do the seeding, and it’s a pretty simple operation.

1. Mow your lawn as short as possible.

2. Rent a dethatcher and run it over the lawn. This machine rips out old, dead stems and leaves, exposing bare soil between the remaining healthy grass plants.

3. Apply a starter fertilizer.

4. Seed the fine fescue grass at 1 lb. seed per 100 square feet.

5. Top-dress the lawn with a fine layer of bagged compost.

6. Water daily, one or two times each day, until the grass germinates and grows to an inch or two of height.

7. Gradually reduce watering. Once you’ve mowed once or twice, you can revert to your regular watering schedule.

Timing this whole project just before a rainstorm in October or early November virtually guarantees success.

A final option is to consider a meadow. These fine fescues make very attractive groundcovers when left unmowed. On my rural property I have a large area where I seeded chewings fescue, hard fescue (a pasture grass), and creeping red fescue. I water as little as every two weeks in the summer. We allow it to grow long for an informal look. Once a year, in the spring, my strapping son rents a high-wheel mower from JB’s Power Equipment and mows the whole thing to prevent flowering and to manage any weeds that might be trying to poke through the grass.

It’s a great area for throwing balls for our dogs, and kids of all ages love to lie on the soft green grass. It’s very active with wildlife: last year when he mowed it praying mantids were scattering in all directions. Swallows fly above the field each evening. Unmowed grasses are important harboring sites for beneficial insects.

The UC Davis Arboretum is establishing a large area of California native grass in a meadow at the edge of the lawn area near the oak grove on the west end. They’re using Blue grama (Bouteloua gracilis). Other options include native strains of Festuca californica and Festuca rubra (there are those fescues again). These are available as small plant starters through Suncrest Nurseries, a wholesale grower in the Bay Area. And many larger ornamental and native grasses can be used for informal meadows. The key is to plant a mowable, walkable, lower-growing species where you’d be walking on it, and then plant some of the taller ornamental grasses on the edges.

We need to rethink lawns. Not necessarily get rid of them, but put them where we use them. Create the effect we want with lower-water grasses. And develop a new culture: less clipped, less formal, more appropriate, more sustainable, and less expensive.

You can find previous columns about low-water plant choices in the Enterprise archives. Look for the October and November 2011, and January 2012 columns. They are also available at http://redwoodbarn.com.

A work in progress: the UC Davis Arboretum is converting a large part of the lawn at the west end to native grasses. Please don’t walk on it while it’s establishing! This species should be able to grow and look good with much less frequent watering than traditional turf.

Our meadow of fine fescues. This area was seeded with chewings, hard, and creeping red fescues. The first two form clumps, the latter spreads. The effect is informal, great for playing with dogs and kids.

Here creeping red fescue has been seeded pure in a shaded area and allowed to grow without mowing, making a soft ground cover. Creeping red fescue is more tolerant of shade than most other lawn grasses.

The leaf blades of the fine fescues. The individual blades are rounder and much narrower than other grass species. You may already have these grasses in your lawn, as they are often added to seed blends for their shade tolerance.

Many ornamental grasses can be planted, preferably in groups or masses, on the edges of lawn areas to continue the visual effect. Most are much more drought tolerant than traditional turf species. Here is a specimen of Nassella tenuissima (formerly Stipa tenuissima), a fine-leaved ornamental grass.

c 2012 Redwood Barn Nursery

www.redwoodbarn.com

Garden Questions in Early Summer!

I heard the “climate zones” have changed because things are getting hotter. Which zone are we in now?
Recently the USDA Plant Hardiness Zones were changed to reflect the warmer winters that have been observed in many parts of the country. No changes were made to California zones, because winter temperatures have not warmed in most parts of our state. The major changes have been observed in the southeastern U.S.
Western gardeners generally use Sunset Zones, not USDA zones. USDA zones only reflect winter low temperatures. Sunset Zones, created by the publishers of the Sunset Western Garden Book years ago, are much more detailed, showing the differences caused by local geography. Davis is in Sunset Zone 14: a hot interior climate with strong coastal influence (the delta breeze that we all appreciate so much on summer evenings). Woodland is in Sunset Zone 8: less coastal influence. For winter hardiness purposes, both are in USDA Zone 9.
So a recent comment in a gardening article in the Sacramento Bee got me curious. From the June 12 edition, in an article titled Gardening's Busy Season Starts With Understanding Climate, an author from the Bay Area is quoted, "Our weather is changing. I've lived in Alameda my whole life, and it's not the same climate I grew up with - it's hotter. We have to adapt. It's one more challenge for gardeners."
Well, the statistics don't actually show that for many parts of California, and particularly not for coastal areas such as Alameda. 30-year temperature data compiled by the National Climate Data Center shows average temperatures have dropped in California's coastal cities and areas such as Davis and Sacramento that have strong coastal influence, while temperatures have increased slightly in interior cities such as Fresno and Redding that don't have the delta breeze. Reasons? Perhaps the Pacific Decadal Oscillation, of which we are in a cool phase.
Bottom line: California gardeners needn't worry about reports of gardening zones changing. Your old books are still valid.

Question from another plant pro: Thrips on roses. What is your experience and what would you recommend to a homeowner to manage the situation? They used the Bayer 3 in 1 product 10 days ago.
Thrips are tiny insects that feed on the tips of the rose buds before they open, causing the petals to distort and the flowers to open imperfectly. Pull back the petals and you will see fast-moving very skinny insects less than a quarter-inch long inside the bloom. Thrips in our area show up on flowers as the nearby grasses dry off in late spring and they move into our gardens looking for food; they are worse on light-colored roses than dark ones.
Spraying with anything is likely to delay the population increase of the natural predators. It isn't the answer the gardener wants, but it's the honest one. We all need to stop selling and using the combination products due to their environmental harm and unintended consequences.
Bayer 3 in 1 is a combination insecticide, miticide, and fungicide. The insecticide part is taken up into the plant and poisons the insect after it feeds. Since it has to feed first, and the feeding is what causes the damage, you still get the damage. It is one of the very worst combinations a gardener can apply with respect to harming bees. Combine tau-fluvalinate with tebucanazole and imidacloprid? Toxicity of the first ingredient to bees increases something like 1000-fold when combined with SBI fungicides such as tebucanazole. And the imidacloprid itself is known to be harmful to bees. So we have a gardener unnecessarily applying a miticide and a fungicide to a plant on which the only identified pest is an insect, and doing significant harm to bees and other beneficial insects with a product that will only marginally manage the thrips (if at all).
Neem sprays might help, since they could smother existing thrips and repel any new ones. Vigorous washing of the plant might help, and will reduce aphids and mites in any case. Ace hardware stores sell a hose-end pressure washer that is great for managing pests on garden plants. More to the point, thrips season will pass. Beneficial insects populations will catch up with the thrips, hot weather will reduce the reproductive rate of the pest, and your roses will be back to normal again.
Bottom line: there is no conventional pesticide, labeled for thrips or not, that gives good control on roses. The damage is done to the blossom before the pesticide takes effect, even if it works. Thrips populations develop resistance to pesticides very quickly. Some products have very adverse effects on beneficial insects. I know garden center professionals want to sell a solution to a problem, but often I find myself explaining that we don't have one. These problems tend to be seasonal and of short duration.

A dwarf Butterfly bush? Wowzer!
We appreciate your enthusiasm. Yes, breeders have achieved short, compact-growing Buddleias. Commonly called Butterfly bush, Buddleias have been long-time garden favorites for their long season of bloom, fragrance, attraction to hummingbirds as well as butterflies, and tolerance of heat and drought. But even the most compact types got to 5 to 6 feet tall, and the older ones were even taller and rangier.
Enter the Buzz Buddleias, and the Flutterbye Petite Buddleias. Little three-foot mounds of color, blooming non-stop from May through summer. Available in purple, lavender, pink, and white, these can be kept in containers or planted in the front of the border. Mix them with lavender, rosemary, rockrose, or other sun-loving low shrubs and perennials.

My clematis came up and bloomed real nicely, and now it's set those seed things. How can I get it to bloom again? Do I have to cut those off?
That plant won't bloom again this season. Each clematis variety blooms for a few weeks. But there are varieties available for bloom at different times spring through mid-summer. The seedheads are interesting and sort of attractive; removing them is tedious, unnecessary, and won't yield any further bloom.
Clematis have a reputation for being fussy. They're not, really; they just like their roots in rich, loose soil that is shaded a bit, and they need regular watering. The tops are fine in full sun or partial shade. Once established, they can be very long-lived and carefree.
Most types put on vigorous growth in just a few weeks in the spring, then bloom, and then rest for the remainder of the season. So the key is to keep the root system healthy and vigorous to build up the plant for the next growing season. Fertilizing in late summer with an organic plant food will help make a more robust plant the following year.

I bought some moss ground cover and planted it in the shade, and it isn't doing well. Looks like it's dying. Is it not getting enough water?
Wrong plant, wrong place. Or if you prefer: misleading common name. Irish moss and Scottish moss (varieties of Sagina subulata) are actually not mosses at all. They are in the carnation family and prefer full sun and slightly dry conditions. For a soft green look in moist shade, try Baby's tears (Helxine soleirolii).

My tree in my lawn has never grown as well as the others. Should I feed it? Why do you recommend keeping grass clear away from trees?
Grass roots compete significantly with tree roots! Trees planted with grass growing up to their trunks grow as much as 30% more slowly than those with the grass cleared. Feeding trees in the lawn is very difficult because grass roots are very efficient at 'stealing' nitrogen. You end up feeding the grass, not the tree. Clear the grass from an area at least 3 to 4 foot diameter around each tree. Then you can fertilize a young tree, using an organic source of nitrogen in spring and/or fall. Established trees need no feeding unless they show specific deficiency symptoms.
Trees in grass are also vulnerable to damage from power equipment such as mowers and especially weed trimmers. Repeated damage harms the water and food conducting part of the tree (the cambium) and stunts it, and creates an avenue for disease to enter. Finally, grass or mulch up against the stem of any plant traps moisture, inviting crown rot fungus. Trees and grass don't mix!

For further reading:
To check out the new hardiness zone map, visit http://planthardiness.ars.usda.gov/PHZMWeb/

Want to see the differences from 1990 to 2006? For an interactive map, visit: http://www.arborday.org/media/mapchanges.cfm

Article about climate data: http://www.sacbee.com/2012/06/16/4557398/gardenings-busy-season-starts.html#storylink=cpy

For more on pesticide interactions: http://www.extension.org/pages/61004/miticide-and-fungicide-interactions

Dwarf butterfly bush is a great new addition to the dry, sunny flower border. Shown here with Euphorbia Ascot Rainbow is the variety Buzz Purple. These compact shrubs grow to three feet or so with equal spread. Butterfly bushes bloom on new growth, so they can be trimmed or cut back as needed. Hummingbirds and butterflies love them.

Here is the Buzz Buddleia in front of a more typical butterfly bush. The tight growth habit, with smaller leaves, leads to a mound of grey-green leaves and continuous purple flowers from spring through summer. These new dwarf hybrids are sterile, so blooms are more abundant (no energy going into seed production), and they won't reseed.

As of late June, our Clematis Ville de Lyon has been blooming since late May and will continue for another couple of weeks. The flowers are followed by interesting seedheads. Clematis like soil that has been enriched with compost, and the roots prefer shade. But the tops can grow up into full sun, or will bloom adequately in partial shade. Established vines can give dozens of blooms over several weeks, with varieties that start in early spring and others blooming in summer.

Clematis montana hybrids bloom in spring, usually March to April. The blossoms are smaller than later hybrids, but more abundant. The blooms smell lightly of vanilla. The Montana hybrids are unusual in that they bloom on old wood, so they should be pruned only after they have finished flowering. The pink flower shown is C. montana Mayleen, and the white one is C. montana grandiflora.

The Viticella hybrids bloom mid-summer, after most other Clematis are done. This plant, a variety called Polish Spirit, is scrambling all down a Nandina hedge on the north side of my house, and provides dozens of blooms over several weeks. Clematis naturally like to grow behind other plants, climbing up onto shrubs, trees, or climbing roses. They are light and open, so they don't suffocate the plant that is supporting them.

It's called Irish moss, and it looks like moss, but students of botany will recognize that it can't be a true moss: mosses don't flower! It's actually a ground cover in Caryophyllaceae, the carnation family. Irish and Scottish mosses prefer full sun.

For a mossy-looking ground cover for moist shade, try Baby's tears. It looks delicate, but can actually spread pretty freely in the shade. Baby's tears won't tolerate direct sun, and may frost back a bit in winter (but aways recovers). Great around stepping stones or with ferns and woodland flowers.

Wednesday, July 4, 2012

Succulents and Cactus!

Succulents have always been in my life.

We were the only ones with a cactus garden in our front yard. My parents were way ahead of their time for a water-appropriate Southern California landscape. Actually, it is a succulent garden, including cactus. Some were fuzzy, some showy, and a few were really spiny. Lots of kids encountered the latter during neighborhood games of kick-the-can.

I vividly recall backing into the business end of a century plant's spine once. In the front my folks had planted 5 or 6 century plants (Agave americana) in the early 1950's. A couple of decades later these all flowered at once, with 30' spikes opening into giant candelabras of blooms wildly attractive to bees and hummingbirds. After flowering the main plant dies, creating a giant cleanup mess, though several new 'pups' have usually formed at the base to replace it. But we pulled out most of them at that point � with a Jeep and a chain.

Once that was all cleared out, my mother kept planting interesting succulents and cactus. Some of her plants came from my grandfather. With a greenhouse in Pasadena and a garden in Palm Springs, he was an ardent cactus collector who also dabbled in other succulents. One of my reference sources for this is The Cacti of the United States and Canada (Lyman Benson, 1982), which he gave me with great pride as he had provided several of the photographs to the author.

When mom turned 50, I gave her Jacobsen's Lexicon of Succulent Plants and she was off and running. Rekindling her interest, she began collecting and propagating. Then she discovered that local nurseries would buy flats of them. Additional greenhouse space was built on their suburban lot. She finally phased back the production part a couple of years ago. At one point she confided in me that The Manual had turned out to be her most significant birthday present. Flowers and candy? Ha!

So you'd think I'd have written about succulents and cactus by now, pretty much having been hard-wired for them. And suddenly succulents are popular again. It's easy to see why.

• Interesting colors and textures.
• Low water use. Replacing your lawn with Sedum spurium or Delosperma cooperi could save over 15,000 gallons of water a year (but you can't walk on it much).
• Spectacular, sometimes bizarre flowers. Asclepiads trap pollinators in cage-like flowers. Stapeliads smell like rotten meat to attract flies for pollination.
• Easy to grow. They can go weeks without water.
• Ridiculously easy to propagate.

A stem stuck in dirt will grow, or often just a leaf. I remember my son watching his grandmother "sticking" cuttings, and he asked in wonder, "so I can just stick this in dirt, it'll grow roots, and someone will buy it?" Welcome to the nursery business, my boy.

They are slowly shedding their reputation as collectors' plants, or something gathering dust in a pot in grandma's garden. I am happy to see succulents moving out into the regular landscape, providing a foliar foil for grasses and Agapanthus, or providing little points of contrast among annual and perennial flowers.

Succulents are plants which store water in modified stems and leaves. It is an obvious adaptation to dry climates, and succulents are heavily distributed in the "horse latitudes:" the subtropical latitudes about 30 - 35 degrees north and south of the equator, where winds are light and the weather is relatively dry. Most of the world's great deserts are in the horse latitudes.

Since we're a little north of that latitude (at 38 degrees N), it is important to know which of the succulents are subtropical and need winter protection. Some well-known succulents need to come indoors before frost, or be grown in a protected microclimate:

Aloe vera:

grown for the medicinal leaves. Other Aloes are hardy, but not this one.

Ceropegia linearis woodii (Rosary vine):

heart-shaped leaves, strange fly-trapping flowers.

Crassula argentea (Jade plant):

elegant container plant has several varieties.

Kalanchoe:

some with fuzzy leaves (Panda plant, Felt plant), others with showy flowers; all are tender.

Senecio rowleyanus (String of pearls)

To simplify: before Hallowe'en move the fuzzies inside and the jades to the porch. Cold is bad, but cold and wet is worse as they'll rot. A screened porch protected from rain is a great place for a collection of succulents.

Lots of unrelated types of plants are succulents. To answer a common question: the difference between succulents and cactus is that all cactus are succulents, but not all succulents are cactus. Cactus are all members of one family: Cactaceae. Other succulents come from many families, ranging from lily to cucumber. Many plants have stems or leaves which store water, but aren't considered part of this group. Impatiens and begonias have "succulent" (i.e., juicy) stems. But they lack the thick cuticle, or skin, that protects the plant from drying and enables a true succulent to withstand long periods without water. One oddity about succulents? They can store carbon dioxide to transpire at night, producing oxygen when most plants are producing CO2.

Popular succulents such as Hen-and-chicks (Echeveria) are leaf succulents:

The leaves are thickened to store water, often coated with light-colored powder or hairs that provide protection from sun. Those without such natural protection are better in partial shade here. Flowers range from very showy (Kalanchoe blossfeldiana) to insignificant.

Cactus are stem succulents:

The stem has a large amount of soft living tissue to store food and water, and very little woody tissue. Cactus don't have leaves (with some exceptions), they have spines clustered on areoles. In the wild they have shallow, wide-spreading root systems. Early botanists measured one young, 5-inch-tall Saguaro (Cereus gigantea) whose roots had spread over 15' in all directions, at only four inches depth!

The roots can form water-absorbing root hairs extremely quickly, then lie dormant for months until the next rainstorm. This enables them to sit in a pot in your garden for many years with only occasional care; I have a cactus that has been in the same pot for 40 years. Many cactus have spectacular flowers, and most have fleshy, juicy fruit. Prickly pear fruit is delicious, but the spines must be carefully removed first!

Cactus spines provide sun protection, along with the same kinds of powdery coatings and fine hairs found in other succulents. Old Man cactus has extra-long white hairs as well as spines. Again, if the variety you are buying has unprotected fleshy parts it may be best in partial shade here.

Day-blooming cactus often have very showy flowers in shades of pink, red, or yellow. Look for Echinocereus, Lobivia, Mammillaria, Rebutia and more. Night-blooming types, pollinated by moths, usually have white or pale yellow flowers, often very fragrant, on very large plants.

Succulents, including cactus, can be grown as houseplants. They require the brightest light you have, and some may lose their color or coating in low indoor light. Paler growth and stretching are signs the light is too low. The biggest risk is overwatering. For indoor growing, plant in a fast-draining potting soil, either one made specially for cactus, or by adding 1 part pumice or perlite to 3 parts regular potting soil. You can mix a bunch of interesting types together in a pot to grow as a living bouquet of foliage, removing any that get too big. Or take cuttings as the plants get tall.

On the other hand, if you're growing them in pots outdoors, here's a trick to reduce how often they need water. Add some clean topsoil to the mix at about the same proportion as the pumice. It will help retain moisture, so you can go weeks (or months?) between waterings and the plant will survive.

Cold-hardy succulents for our area (Sunset Zone 14, USDA Zone 9) include:

• Aptenia cordifolia (Red apples): a vigorous ground cover with red blossoms.
• Echeveria (Hen-and-chicks)
• Graptopetalum: large pinkish leaves.
• Sedum (Stonecrops): one of the most useful groups of ground covers.
• Sempervivum (Houseleeks): like little hen-and-chicks, great in pots.

Agave, Aloe, Euphorbia, and Haworthia vary as to hardiness.

Cactus are all from the Americas (with one weird exception), and range from the tropics to very cold northern latitudes and high elevations. Most can live outside here if protected from rain during the winter, so keep them under an overhang in the winter. The combination of cold and wet can lead to rot. Christmas cactus are semi-tender, about as hardy as Jade plants.

Note to parents:

some members of the genus Euphorbia have very irritating sap. Certain cactus contain toxins and hallucinogens. If your kid gets interested in cactus and other succulents, you may wish to monitor which species he or she collects.

There is an excellent collection of succulents open to the public right here in Davis, at the Botanical Conservatory at UC Davis. Visit http://greenhouse.ucdavis.edu/ for more information.

Oddities:
Caudiciforms are a weird group of water-storing plants that have woody enlarged stems (caudex), sometimes getting quite large. With age these can get very large and quite valuable.
Examples: Adenium obesum (Desert-rose), with oleander-like flowers (it is related, and also has poisonous sap like oleander).

Neither of these are true palms, despite the common names:

• Beaucarnea recurvata (Ponytail palm)
• Pachypodium lamerei (Madagascar palm)

Other caudiciforms have extra-large surface bulbs, from which new growth sprouts seasonally. People who get really serious about succulents and cactus tend to also collect caudiciforms because of the bizarre swollen stems.

Cresting, or fasciation, is a natural mutation of the growing point of a plant, occurring for unknown reasons in many types of plants. I've seen this flattened, distorted new growth on species ranging from fruit trees and roses to a hollyhock (the flower stalk flattened out, then split in two parts which coiled away from each other to create a Dr. Seuss mallow!). Because of the center-out growth habit of some cactus and euphorbias, this can cause interesting distortions. Which, of course, increases their value to collectors.

Tuesday, June 5, 2012

You Can Grow That!

The 4th of each month is You Can Grow That day! Here's what all the bloggers came up with this month.... http://wholelifegardening.com/blog/2012/06/05/garden-bloggers-you-can-grow-that-day-june-2012/

Monday, June 4, 2012

Ten Plants for Early Summer!

Click on any image for a larger version
Slide show of the plants in this article: Click here

As we head into summer, gardeners may be looking for plants that give lots of landscape value with little input. For ease of growth, abundance of bloom, and interesting foliage, here are ten plants I keep coming back to in the months of May and June for garden performance.

1. Buddleia Royal Red (Butterfly bush)
Butterfly bushes draw butterflies, hummingbirds, and bees. They have fragrant flowers, and are reasonably drought tolerant. The new Buzz Buddleias are dwarf, fitting into smaller yards and borders. But I still think Royal Red, which is actually purplish-red, is one of the best for its vibrant color.

2. Canna Tropicana (Canna lily)
I don't even really like Canna lilies for the most part. Ok, they impart a bold, tropical look, but they can look pretty scruffy after the bloom, and the rhizome roots keep pushing outward to make unwieldy-size clumps. But Tropicana has beautiful striped leaves. Great in containers, near water features, or in a border deep enough to accommodate some spread. The bright orange flowers are a nice bonus.

3. Cotinus coggygria (Smoke bush)
This is becoming one of my favorite small trees for patios, dry landscapes, and hot locations. Royal Purple has the most vivid colored leaves. A great substitute for the ubiquitous red-leaf plum, with a more graceful, open habit, and more tolerant of drought. The flowers are in wispy clusters, causing a "smoke" effect. There is also a gold-leaved variety.

4. Hemerocallis Gentle Shepherd (Daylily)
More than 60,000 cultivars of daylily to choose from, and I like this white one? Yes! The clean, creamy-white, very large blossoms are a departure from the usual oranges, reds, and yellows of daylilies, blending with any other color in the landscape. But there are gaudier colors if you prefer. Anybody can grow daylilies!

5. Hydrangea quercifolia (Oakleaf hydrangea)
Grandma's mophead hydrangeas, the giant-flowered types in pink or blue, are fussy in Davis. They get anemic due to the water quality, and require lots of water. The white-flowered Oakleaf hydrangea is a very elegant substitute. It doesn't care about the pH of our water, the foliage is very attractive (and turns a nice red color in fall), and the plant is much more refined than the mopheads. Prefers afternoon shade.

6. Lavandula x intermedia Grosso (Lavandin, hybrid lavender)
Lots of lavenders to choose from, but I especially recommend this one for fragrance and heavy bloom yield. It grows 3 to 4 feet tall and broad. All lavenders are heat-loving and drought-tolerant; in fact, it is easy to over-water them. Keep them dry once established. Grosso, like many of the hybrid lavenders, blooms from May through summer, often into fall.

7. Melianthus major (Honey bush)
Big bold-toothed grey-green leaves, mahogany-colored flower spikes in May. The foliage smells odd, not unpleasant; some say like pasta. Tolerates hot sun, partial shade, drought. Sprawls several feet across if allowed to, but can be cut back periodically for size control.

8. Penstemon heterophyllus Midnight (Summer snapdragon)
Penstemon is one of my favorite perennials, and Midnight is my favorite penstemon. Some varieties aren't long-lived; this one is. I have one plant that is more than ten years old. This is one of those May through July perennials, but it will give another fall bloom if you remove spent bloom spikes. Hummingbirds and the big solitary bees love penstemons of all kinds. Full sun or partial shade, tolerant of drought or average watering. Give 'em room: each of my plants is about 3 feet across.

9. Phlomis fruticosa (Jerusalem sage)
This is a big, sprawling shrub with attractive fuzzy grey-green leaves and strange, beautiful yellow flowers in whorls over a long period. The flowers smell exactly like carnations! Very drought tolerant, very sun tolerant, moderately shade tolerant. Branches can be allowed to root if you want it to cover territory. If not, cut it back now and then.

10. Punica granatum (Pomegranate)
One of the easiest fruit trees to grow, pomegranates always remind me in May and June how attractive they are in the landscape as they sport large, bright orange-red flowers. Then they remind me again in fall as the leaves turn bright yellow and the vivid red fruit ripens. Even if you don't eat the fruit, it is a beautiful landscape shrub or small tree. Pest-free, drought and heat tolerant. Dwarf varieties that set miniature fruit are useful landscape ornamentals.

-- runners up --
11. Achillea (yarrow): lots of new varieties with shorter stature and brighter colors have brought this old perennial back in popularity.
12. Alstroemeria (Peruvian lily): finding new use as a garden perennial, rather than just for cutting, due to a whole spate of new compact varieties.
13. Celosia (Plume flower and cockscomb): psychedelic color range, strange crested forms make these sun-loving annuals favorites for kids.
14. Euphorbia Ascot Rainbow: colorful foliage, chartreuse flowers, compact habit, full sun. Great with succulents.
15. Phygelius capensis (Cape fuchsia): elegant hanging flowers on tall open spikes attract hummingbirds all summer. Not a fuchsia! Much easier and hardier.

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Buddleia is the genus of Butterfly bushes, a group of shrubs tolerant of sun, heat, and moderate drought. Old types grow 6 feet tall or more, and benefit from a hard pruning every year of so. Royal Red, shown here, isn't really red: it is purple with a tinge of red in each small blossom. Fragrant, free-blooming, and very attractive to hummingbirds as well as butterflies.

Canna lilies are noted for their bold, tropical foliage and gaudy flowers. They spread by rhizomes to make large patches. Tropicana has especially attractive striped, colorful leaves, and vivid orange flowers.

Oakleaf hydrangea is becoming one of my favorite shrubs for shady landscape areas. Elegant growth habit, attractive foliage, nice fall color, clean white blooms. A great substitute for the standard hydrangea, which doesn't like our water.

Honey bush is a big, dramatic plant in the landscape! It can tolerate sun or light shade. Interesting for large containers as well.

Penstemon, sometimes called Beard tongue, is a summer-blooming perennial that is attractive to hummingbirds and large solitary bees. Newer hybrids may have brighter, splashier colors, but Midnight is a proven performer in Valley landscapes. Plants shown here are three years old: 3 feet across and tall, blooming from May through July.

Jerusalem sage isn't a true sage, but it's a close cousin. A big plant for sunny locations, growing to 4 feet tall and 5 feet across, but readily trimmed for size. Fragrant blossoms, easy to root, easy to grow.

We need to start thinking of pomegranate trees for their ornamental value! The flowers are large and showy in May, fall leaf color is bright yellow, and the fruit is bright and colorful in fall. I water my pomegranate tree about once a month. The fruit is delicious, and if you don't happen to eat it the songbirds will.

Achillea (yarrow): the variety shown here is Strawberry Seduction, which blooms at about 18 inches tall from summer through early fall. Yarrows attract beneficial insects, make lovely dried flowers, and spread slowly by short rhizomes. Full sun is best.

Written for the Davis Enterprise, May 31, 2012

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