The Best Dogwoods & How to Grow Them

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Alluvial Terrace Nursery

There’s nothing like learning about trees from someone who has discovered for themselves what makes a winner and how to grow it. Recently I had the opportunity to tour a small wholesale nursery near Corralitos. Jon Craig has evolved from Silicon engineer to a propagator of plants and trees and he’s all the happier for it. He laughs when he says he has loved plants for a very long time starting with his first job mowing lawns. As a former engineer it’s all about the research and the plants he grows showcase his success.

His very favorite tree is the dogwood. Not just any dogwood but the ones that bloom with the largest flowers for the longest time. There are four main species of dogwood trees. From the Himalayas in China comes cornus capitata, Korea is home to cornus kousa. Cornus florida grows on the east coast and the west coast is home to cornus nuttallii or Western dogwood.

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Jon Craig with cornus capitata ‘Mountain Moon’

We are all familiar with the Eastern dogwood that blooms early in the spring. It’s beautiful but rain and wind can cut short the flowering season many a year and the root system is prone to disease. Our Western dogwood is prone to leaf spot fungal diseases. The Kousa dogwood is a more drought tolerant, disease resistant and a tougher plant all around. Large, showy flowers open after the tree has leafed out and remain for a long time. This makes it good for hybridizing with other varieties.

The Stella series is a mix of a florida on kousa dogwood roots. Vesuvius series is a cross of our native nuttallii with a florida as is Eddie’s White Wonder. There is also a nuttullii-kousa cross called Venus that displays huge flowers and gets its disease resistance from the kousa roots. All these cultivars strive to produce a tree with superior disease resistance and huge, long lasting blooms.

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Mountain Moon

Deciduous dogwoods don’t like wet feet especially in the winter. That’s how they develop fungal disease. But there’s an evergreen dogwood that can handle moisture all year round. That tree is Jon Craig’s very favorite. With a name like Mountain Moon you can just picture it blooming high in the Himalayas. Huge flowers up to 6” wide can last from late spring into early summer. After flowering, the fruits begin to form and grow into red balls about the size of large strawberries. This is the reason is it also known as the Himalayan Strawberry Tree. They are edible but bland and tasteless to us. The birds love then though and they remain on the tree while woodpeckers and robins have a feast.

Cornus capitata ‘Mountain Moon’ is a tough tree that can handle strong winds and isn’t bothered by any pests or diseases. They enjoy lots of organic matter as do all dogwoods. Many people think of dogwoods as an understory tree but this location is often too shady. Grow them in a full or partial sun location that gets afternoon shade after 4pm. Add a couple of extra drip emitters or inline drip tubing to your irrigation system and they’re happy.

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Ruby Fall redbud

Besides enjoying the hundreds of blooming dogwoods, I learned about a redbud that is not as fussy as the lovely Forest Pansy. Ruby Falls and Merlot promise to be more reliable in the garden and more heat resistant.

Jon will try his hand growing just about any plant that he thinks others will also enjoy. A fine crop of Alice oakleaf hydrangea grew near a block of Michelia ‘Inspiration’ getting ready to flower and scent the air. The lilacs had finished blooming but the peonies were just starting their show. Jon shared a tip about tree peonies he learned recently from a well-seasoned Japanese gardener. He followed her advice and cut back the tree peony stem in the dormant season forcing it to produce new stems. Voila- they are now loaded with flowers.

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peony

Jon grows many other types of dogwood and also Copper beech, magnolia macrophylla, Royal Raindrops crabapple , Sheri’s Cloud nyssa and even a Purple-leaved hazel. I could only fit a couple of 5 gallon cans in my car so a beautiful smoke bush in full bloom and a Black Lace elderberry now call Bonny Doon home. But I have my eye on one of those spectacular Mountain Moon evergreen dogwoods for the back garden.

Planting for Birds and Watering Tips

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Purple finch

My garden is alive with birds. Butterflies and bees also seem to find it an interesting place to visit. I’m always on the look out for plants that will attract even more of these exquisite creatures. Fortunately there are many that have low water requirements which is a prerequisite these days.

But how do you plant something new given the new water restrictions? And what about those existing trees, shrubs and perennials that birds, bees and butterflies depend on? How much water do they need to survive?

Everybody loves winged creatures in the garden. Adding plants that attract birds, bees and butterflies is at the top of the list of requests for nearly every garden that I design.

Trees that provide fruit, seeds, nectar and protein from insects attract many kinds of songbirds. Our native Big Leaf Maple is a favorite of the Evening Grosbeak who relish the seeds and early spring buds. Another bird magnet is the dogwood. Our Pacific dogwood as well as the Eastern dogwood and even the hybrid of the two, Eddie’s White Wonder, all are very valuable sources of food for many birds. Their summer berries are high in fat and important for migratory and wintering birds.

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Achillea

In every garden possible I try to include low water use shrubs and perennials that attract birds. My favorite Lesser Goldfinch is partial to the seeds of yarrow, buckwheat and aster. Kevin’s mahonia is favored by Western bluebirds. Blooming now in our own neck of the woods is Mexican elderberry. Their butter yellow flowers will form purple berries rich in carbohydrates and protein and attract an incredible number of birds. And I always can find space for another variety of manzanita or ceanothus.

Both hummingbirds and butterflies are attracted to flowers that provide nectar. Among their favorites that won’t break your water budget are natives such as penstemon and salvia. Galvezia, mimulus, monardella, California fuchsia and ribes are also important nectar sources for them in your garden. Add a couple non-native, drought tolerant perennials like lavender, gaura, coreopsis, verbena, scabiosa, lantana and wallflower and you’ll provide a feast for all your winged visitors.

So how much water do different types of plants need during the heat of summer?

As a rule of thumb, trees and large shrubs need deep but infrequent waterings. They should be on a separate valve than your smaller shrubs and perennials. After the last two winters of little rain, many trees are showing signs of stress. It’s not easy to replace a tree that will take 20 years to regrow if you have to replant. Water ornamental trees 1-3 times per month depending on the type and soil. Tree roots are 12-36” deep and require 10 gallons of water per inch of trunk diameter.

Apply with a soaker hose, drip system emitters or hand held hose with shut off and soft spray attachment according to your water districts restrictions. Don’t dig holes in the ground in an effort to water deeply. This dries out roots even more. Be sure to water the root zone to the indicated root depth every time you water. Watering deeper than the root zone only means you are wasting water. You can test how deep you watered by pushing a smooth rod -1/4” – 3/8” in diameter- into the ground soon after you irrigate. The soil probe should easily slide through the wet soil but become difficult to push when reaching dry soil.

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Homestead Purple verbena

The roots of smaller shrubs are 12-24” deep in the soil. Established native shrubs may need only monthly waterings to keep them looking their best while other shrubs may need watering every 7-10 days during the heat of the summer. Perennial roots only go down 12” or so and may need watering once or twice a week depending on it’s water needs.

With lots of mulch and the above watering tips you can keep all your plants happy and healthy for everyone to enjoy.

Keeping Gardening Facts Straight

I’ve gotten several emails lately requesting more information about something mentioned in a recent column. I also received a phone call from a reader describing a bad encounter with a certain common plant. She wanted to share her experience so it didn’t wouldn’t happen to anybody else. And a conversation about how bad the poison oak is this year triggered a discussion about how to dispose of the stuff. So here goes. All the news that’s fit to print.

Whether it was Joe Friday who said it or Dan Akroyd in the Dragnet parody. we all want “Just the Facts, Ma’am“.

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ramial bark chips

In my column a couple weeks ago about garden planning for the drought, it was the last line “And don’t forget the… mulch (no shredded bark, please)” that caused a bit of confusion. It’s great that everyone has accepted the value of covering the soil with organic mulch. Organic mulches- such as bark chips, treated sawdust, straw or even grass clippings- keep plant roots cool, encourage earthworms and other beneficial organisms, conserve soil moisture, combat weed growth and protect the soil from erosion.

But is there an organic mulch that is better than another?

There are many types of mulch available. Nurseries sell different types of mulch in bags, building supply yards carry everything from bark nuggets in different sizes to treated sawdust to chipped bark and even shredded redwood bark. It’s the shredded redwood bark, also called gorilla hair, that does nothing for the health of your soil. If you have a very steep slope you may have to go with this type of mulch but that’s the only time I can recommend it. It will cling to a hillside without washing down in winter rains but treated sawdust would also work for this type of terrain and is much better for soil health.

Of all the types of organic mulches out there, recent studies have shown that ramial bark chips are one of the best mulches to improve soil health. Ramial chips come from trees and brush with branches up to about 3” in diameter with or without leaves. These chips contain a high percentage of thin young bark and young wood. This is what makes them so valuable to the garden. Young wood is a tree’s factory for producing protein, glucose, fructose, lignin and polysaccharides. It’s an important source of nutrients for living things at all levels according to a study by soil scientists, G.Lemieux and R.A.Lapointe. You can obtain these kind of chips free from tree trimming companies who are probably working nearby chipping roadside brush for PG&E.

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Euphorbia

About that call from a reader who had a terrible experience after pulling some plants in her yard that had gotten a little out of hand. She said she and her husband ended up with severe eye burn after getting some toxic sap from euphorbia in them. She said they really don’t know if some of sap became airborne while they were pulling stems or if they accidentally rubbed some near their eyes at some point in the day. They went to Urgent Care right away for treatment but the pain lasted for days. She described it as one of the most painful experiences she has ever had. Euphorbias are very deer resistant and drought tolerant and are being used more and more in gardens.

Many of us, me included, grow tropical milkweed or Asclepias curassavica to attract monarch butterflies. The milky sap from this plant protects the monarch from being eaten and can cause the same painful burning of the eye. I read of a case where a gardener’s clothes brushed some stems while she was tending the garden. Later she wiped the sweat out of her eyes and didn’t realize she had also touched her pants. She ended up with cornea burn causing temporary blindness and had to take strong pain relievers and steroids to elevate the pain.

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Poison oak

Lastly, a fine crop of poison oak is growing this year so thick in places you can barely avoid it. The new foliage literally glistens with toxic oils. Many birds relish the white berries that form later in the season. 9 out of 10 people will get a rash if even one drop of urushiol oil touches the skin. And this oil has lasting power. It can stay active on any surface, including dead plants, for up to 5 years. Burning dead or dormant poison oak branches is especially dangerous as urushiol oils released in smoke can produce disastrous results if inhaled. So what to do with the stuff if you pull it out? Do not put it in your green waste can. It can end up being ground into mulch along with other green waste. Instead put it in your gray garbage can. Other plant matter that has to be put in the garbage can is pampas grass and bamboo. Don’t put them into green waste

So that’s the skinny on shredded redwood or gorilla hair, common plants with toxic sap and poison oak disposal. Be careful out there.

Celebrate May in the Garden

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Valthemia bracteata

May is the month for you if you make a note when your favorite plant starts to bloom. May is the month for you if you count the number of hummingbirds at the feeder everyday. May is the month for you if you’ve been waiting for the soil to warm enough to plant melons and peppers and winter squash.

A friend gave me a blue Hokkaido squash last fall and I saved the seeds. I’ve been waiting patiently to plant them. It’s one of the best tasting, beautiful squash you can grow. I’m looking forward to harvesting my own this fall. They store for quite a while, taste great and look stunning in a Halloween display along side orange pumpkins. I can hardly wait.

Plants are growing like crazy this month preparing to reproduce at their given time. The birds, bees and even those pesky tree squirrels are finding lots of food and nectar to feed their young. We know the dry months of summer are coming and are preparing by modifying irrigation systems to conserve water and mulching all bare soil. I think we deserve to set a little time aside between gardening tasks to enjoy the wonder of nature and our own gardens.

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Honey bee collecting pollen

Here’s a task that requires no work at all but the benefits are huge. Set aside a small area of your yard, say 10% or so, and leave it uncultivated. Let it grow wild and see what native plants and wildlife show up. This would be a good spot to plant milkweed and let it self sow for the Monarch butterfly.

Don’t push yourself and bite off more than you can do in the garden at a time. Landscaping doesn’t have to be done all at once. Maybe choose a new tree or a couple low water use shrubs to plant and care for this summer. Choose something that looks good year round to provide interest. Or take one corner this year and another corner next year to redo or install. This won’t break your water budget or your back.

Food gardening is hard work. Maybe this year grow just those edibles that taste so delicious freshly picked from the garden. Edibles like strawberries, blueberries, herbs, lettuces, chard and arugula are ornamental, don’t take up too much room and are easy to grow. I was disappointed with the way my tomatoes tasted last year. They were OK but no where near as tasty as the dry-farmed Early Girls at the Farmer’s Market. This year I’m only going to grow cherry tomatoes. One of life’s simple pleasures is picking and eating your own fruit as you work in the garden. Beside my favorite Sungold I’m going to try growing local heirlooms like Chadwick’s Cherries, and Camp Joy.

Don’t get me started on the weeds this year. With those early fall rains everything you don’t want in the yard is going nuts. I have actually been gaining ground on controlling many of the annual weeds around my house. The soil is soft and the smaller root system is more likely to let go so as I walk around I pick a few or as many as don’t seem like work. Each plant can produce so many hundreds of seeds that I think of it as free exercise.

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Azalea blooms

When the last flowers of your rhododendron, azalea, camellia, weigela and spirea have finished it’s time to prune them. If you prune just before the plant blooms you risk removing that year’s flowers. If you prune several month after flowering your risk removing the flower buds forming for next year. Basically it’s best to prune a bit each year to shape and thin the plant. The rules apply to most plants. Prune to the next whorl or set of leaves. There’s no need other than looks to deadhead old flowers.

It was great to get a bit more rain last week. Plants appreciate the moisture especially during spring. Come summer everything slows down to survive and that’s a part of our unique climate here, too.