Sneeze-less Landscaping

It was brought to my attention by a reader who suffers from pollen allergies that blooming acacias are not the cause of allergic reactions at this time of year. Acacias are largely pollinated by insects and their heavy pollen doesn’t tend to become airborne. It’s the non-showy, quiet ones you have to watch out for.

Evergreen clematis blooming below flowering pear tree.

About 25-30 popular landscape plants are responsible for the majority of plant-related allergies in California. During the height of the pollen season- from late February to June- there are often thousands of pollen grains in every cubic meter of air. One can breathe hundreds of them with every breath. Though pollen can travel many miles, the majority tend to stay in the general area of their origin.

Redwoods, oaks, alders, ashes and other wind pollinated trees like olives, birch, box elder, cypress, elm, juniper, maple, fruitless mulberry, pine, walnut, willow and privet are the major source of spring pollen. Most native plants are good in the sneeze-less landscape but if you have bad allergies or asthma it best to avoid wind-pollinated ceanothus, elderberry and coffeeberry.

You may not be able to avoid those culprits growing on other’s property but you can get the most out of your own backyard by creating a sneeze-less landscape. Replacing existing plants may be impractical but planning future plantings with these things in mind will save you a lot of headaches down the road and let you enjoy the sunshine outside in your garden.

Clematis armandii or Evergreen clematis flowers

Flower type is a good way to judge plants. The best looking flowers usually cause allergy sufferers the fewest problems. Plants with bright, showy flowers are usually pollinated by insects, rather than by the wind. These flowers produce less pollen and their pollen is larger and heavier, sticking to the insect rather than becoming airborne and lead to sneezing, a runny nose and watery eyes.

Some trees that are good for anti-allergy gardens are apple, cherry, dogwood, magnolia, pear and plum. Shrubs like azaleas, boxwood, lilac, rose-of-Sharon, hydrangea and viburnum are also not likely to cause problems. Good flower choices include alyssum, begonia, clematis, columbine, bulbs like crocus, daffodil, hyacinth. Also dahlia, daisy, geranium, hosta, impatiens, iris, lily, pansy, petunia, phlox, roses, salvia, snapdrag

Salvia ‘Bee’s Bliss’ (good)  Ceanothus ‘Heart’s Desire’ (bad)

on, sunflower, verbena and zinnia. Lawns of perennial rye grass, blue grass and tall fescue blends are usually OK as they will not flower unless allowed to grow to 12″ or higher. Bermuda grass, on the other hand, can pollinate when the lawn is very short, sometimes as quickly as a few days after mowing.

Hopefully, our rainy weather will not cause problems for allergy sufferers. Symptoms may become worse if the body reacts to the disappearance of the pollen following its initial appearance only to have to have more of it later in the spring. According to Dr. Stanley Fineman, an allergist with the Atlanta Allergy and Asthma Clinic, “You become sensitized to it, so when you’re…re-exposed, you can get an even more violent allergic reaction.”

Here’s to a sneezeless spring for you allergy sufferers.

Garden Tasks-Rain or Shine

Those of you who lived in the Santa Cruz mountains during the winter of 1982 remember it well. Following two days or torrential rains, a large section of hillside above Love Creek gave way. Thirty homes were destroyed and ten people were killed by the slide. The rainfall totaled 111 inches that year.

Rain gauge on 2/8/17 showing 99.99″ +10″ more as of 2/18/2017

During the winter of 1997 the San Lorenzo Water Department recorded 90 inches of rain. The department’s historical rainfall data goes back to 1888 and shows that during the winter of 1889 a whopping 124 inches of rain fell. This winter is one to rival the books with about 70-110 inches of rain falling so far depending where you live. We don’t aspire to break any records.

How does this much rainfall affect our gardens? If you have addressed drainage issues and are slowing, spreading and sinking all this water, congratulations. But what about the plants? Fortunately most plants are dormant or semi-dormant at this time of year. Even plants that don’t lose their leaves aren’t in growth mode yet. When a plant is actively growing either roots or new foliage it will suffer if the roots are soggy day after day. Fungal problems and root rot will take its toll on a plant. An extremely wet March or April is not a good thing.

We gardeners are the eternal optimists and hope that only gentle rains will fall through May. And during those lulls in the weather this is what I’m going to be doing over the next month.

California fuchsia – zauchneria californica

Prune fruit, nut, shade trees and deciduous vines like clematis. Cut back woody shrubs like Mexican bush sage, artemisia and butterfly bush to stimulate lush new growth. You can cut back these plants close to the ground. Don’t use this approach on lavender or ceanothus, though. Prune them lightly after blooming without cutting into bare wood.

Prune fuchsias back by a third and remove dead, crossing branches and interior twiggy growth. Container fuchsias can be cut back to the pot rim.

mophead hydrangeas in June

Cut back hydrangeas stems that bloomed last year and apply a soil acidifier if you want the flowers blue. Although sulfur is the traditional favorite for quickly acidifying soil it is not as kind to many beneficial soil microorganisms. Coffee grounds, pine needles, peat moss and cottonseed meal are better for your soil.

I’ll wait to prune back perennials that may have their new foliage damaged in a late frost. Already damaged foliage can protect a plant from further frost damage. Mid-March is the estimated date of last hard frost in our area. Or at least it used to be.

Don’t cut back grasses yet if you get frost in the area where they grow. Wait until mid-March. If you live where you rarely get frost go ahead and prune these plants back now. I’m going ahead and pruning California fuchsia, salvia ‘Bee’s Bliss’ and hummingbird sage now. They look terrible.

camellia sasanqua

Don’t prune spring flowering shrubs and trees like lilacs, flowering cherries, plums and crabapples, rhododendrons, azaleas, camellias, weigela or spirea until after they flower. You can cut some branches during flowering to bring in cuttings for bouquets.

I can tell that spring will soon be here as the flowering plum buds are showing color. Can’t tell from the weather report, though.

About Roses

Roses are the flower of love. Many of us have fond memories of favorites in our mother’s garden or of a beautiful bouquet given or received on Valentine’s Day. It’s dormant season for roses which is good for both pruning and adding a few to the garden.

David Austin rose

As a designer I have clients who have inherited roses and want to keep them as a remembrance. Others want to create a cutting garden filled with roses and other perennials. Don’t feel guilty for growing those beauties in your own garden. They use less resources than you think and there are many ways to grow them sustainably.

Roses, whether bush types, climber or ground cover carpet varieties, use a moderate amount of water in order to thrive according to the latest Water Use Classification of Landscape Species (WUCOLS) list. This amount of summer irrigation is the same as many of the plants on the list of Scotts Valley Water District’s 800 Approved Low Water-Use Plants for lawn replacement. Plants such as Emerald Carpet manzanita, Joyce Coulter ceanothus, Siskiyou Blue fescue grass, Pacific wax myrtle, butterfly bush, yarrow hybrids and Tapien verbena have similar water requirements.

Since now is the time to prune your roses here are a few tips.

Strike it Rich hybrid tea rose

Prune shrubs moderately to keep them compact. The goal is to keep the center of the plant open for good air circulation aiming for a vase-shaped bush with an open center. Cut out canes that cross, appear weak or are diseased, spindly or dead. Healthy canes appear green or reddish while old and dying canes are brown. Cut back the remaining stems by about one third. When pruning, cut canes at a 45-degree angle just above an outward facing leaf bud or a swelling on the cane. Clean pruners after every use to prevent the spread of disease and keep your pruners sharp.

Prune heirlooms roses such as David Austin and other old antique garden roses less because their open look is part of their charm.

Same goes for climbing roses. Cut out extra stems if there are too many and also cut back long established canes to about the place where they are slightly thicker than a pencil. Then cut each side stem down to several inches. This will make the cane flower along its complete length for a beautiful spring display.

Zepherine Drouhin climbing rose

Pluck off and rake away any old leaves. They can spread fungal spores. Consider spraying dormant plants with a combination of organic horticultural oil and copper soap or lime-sulfur. If you usually only have problems with black spot you can use a mixture of 1 teaspoon baking soda with a few drops of light horticultural oil in 1 quart water and spray every 7 to 10 days during the spring.

Prune your roses throughout the growing season, too. Deadheading, or cutting off spent flowers, encourages plants to re-bloom. Mulch around your roses to conserve water and encourage soil microorganisms.

Don’t worry whether you’re pruning job is perfect. Roses are super forgiving and you can always trim them up again later.

Take Advantage of Bare Root Season

Take advantage of those rare breaks in the weather to get basic chores in the garden done. Who thought last fall we’d be wishing for less precipitation or at least that it would be spread out over a longer time? Looking back at National Oceanographic & Atmospheric Administration (NOAA) winter season predictions from last November, their best guess was that our La Nina condition was weak and drought was expected to persist in California. Let’s hope our record rainfall makes its way down into the aquifer.

What should a gardener be doing between rain storms?

bare root fruit trees displayed at Mountain Feed & Farm Supply in Ben Lomond

Shop for bare root plants. If you want to add fruit trees or other edibles to the garden and the weather has interfered with your plans don’t delay. Shop for your plants now while they are still dormant. Once leaves emerge or flower buds start to swell tree roots have already started growing. You want your tree to start developing permanent roots in their new home. Stone fruits such as apricots, peaches, plums and cherries are going to start waking up first so they are best put in the ground soon. Fruit trees like pears and apples wake up later so you can wait a bit longer to plant those varieties.

Don’t plant in heavy saturated soil with a high clay content, however. If your soil drains poorly it’s best to place your bare root tree at an angle in a trench, cover with soil and water in. Wait to plant until the soil is crumbly and friable with plenty of pore space. Digging in waterlogged clay soil is one of the worst things you can do for your soil’s health.

What’s the correct way to plant a bare root tree? According to research amending the soil is no longer recommended.  Mountain Feed & Farm Supply in Ben Lomond has a great web site with all the information you need to get your new fruit trees off to a good start including pruning, staking, mulching and care as they mature.

Red Delicious apples

What fruit tree varieties can you grow here in the mountains? Well, almost everything. Most of us get 700-1200 chilling hours where the temperature is 45 degrees or less during the dormant season. You can find out how many hours of chilling your area gets by going online to www.getchill.net and use the WunderMap from Weather Underground. You can give a fruit tree more chilling in the winter but not less. Those in coastal Santa Cruz, for instance, can grow Fuji apples as they require only 300 hours of chilling but not Red Delicious. We can grow both.

Ginger Gold apples

What if you don’t get full sun where you’d like to grow fruit trees? Apples, pluots and plums are good choices for an area that gets some sun- at least 5 hours- every day during the growing season. The ideal is full sun but these trees will still set and ripen some fruit in partially shaded conditions. With peaches, nectarines or apricots it’s a different story. These fruits need hot sun to develop sweet, tasty fruit. Too little sun and they will not deliver anything close to what you have in mind.

Don’t miss the opportunity to add a fruit tree or other edible to your garden this winter.