Pollen & the Allergy sufferer

Contrary to popular belief acacia trees are not to blame for spring allergies

The acacia trees are in full bloom. Being one of the first flowering trees we see they get our attention. Blooming acacias are often blamed as the cause of allergic reactions at this time of year but acacias are largely pollinated by insects and their heavy pollen doesn’t tend to become airborne. It’s the non-showy, quiet plants you have to watch out for. If you’re an allergy sufferer some plants are worse than others for you.

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 pollens 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 sneezeless 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 properties but you can get the most out of your own backyard by creating a sneezeless 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.

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 in 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 good are dahlia, daisy, geranium, hosta, impatiens, iris, lily, pansy, petunia, phlox, roses, salvia, snapdragon, 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 inches 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.

This year we’re not lacking for rain thankfully. Symptoms can become worse for the allergy sufferer 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.

Tough Flowering Plants for Rain & Snow

It takes a pretty tough plant to flower in heavy rain let alone snow. How do they do it? After getting well over an inch of snow last week at my house up here in Bonny Doon all I know is I want more of these steel-clad plants in my garden.

Helleborus orientalis blooming in the snow

I garden in pretty tough conditions- light wise- not receiving sunlight for 6 months of the year. Still I have winter daphne, helleborus, abutilon, loropetalum. Autumnalis flowering cherry and choisya blooming now. The pansies, cyclamen and primroses are looking a bit beat up but they’ll bounce back. These are my winter flowering heroes.

After the snow melted I have to say the hellebore help up perfectly. I received a couple new ones last year for my birthday. Wish I had saved the tags. The double burgundy one is lovely. One of my favorites is called Cinnamon Snow but all of the varieties of this buttercup relative accept wind, rain, cold and less than perfect soil while getting by with only moderate watering in the shady summer garden. Deer aren’t attracted to them either

I had to wait a couple years for my variegated winter daphne to settle in before setting flowers but beginning last year it’s making up for lost time. There’s something special about a plant that will bloom in the depth of winter, hold up to rain and scent the garden all at the same time. With beautiful rosy-pink flower clusters and attractive yellow-margined variegated foliage, daphne make a great foundation plant for dappled shade gardens. They are deer resistant and have low water requirements during the summer. What’s not to love?

Another tough plant that can take weather extremes is the Lily-of-the-Valley shrub (Pieris japonica). There are many varieties of this early winter bloomer. Some have pure white flowers, other sport various shades of pink or dark rose. Mine is the smaller variegated foliage model with dainty, drooping clusters of pure white flowers in early spring. Right now it is covered with flower buds so dense that you’d think it was already blooming. The new growth in the spring has a beautiful pink tint. This shrub will hold up to the wildest weather. Another plus for the Lily-of-the-Valley shrub is that is useful for firescaping in the landscape and it isn’t on the menu for deer either.

Pink Australian fuchsia bloom profusely despite the rain, I added a variegated variety called Correa ‘Wyn’s Wonder’ to my own garden a couple years ago but I was cavalier about protecting it from gophers and alas it is not with me anymore. Still it’s a great plant. Although not related to hybrid fuchsias, the flowers are similar and their nectar feed the Anna’s hummingbirds when there’s not a lot of plants blooming for them. Australian fuchsia grow well in dry shade under oaks are deer resistant and drought tolerant.

I keep threatening to get a mahonia aquifolium. It would be perfect up here. They are a favorite of birds and indoor floral arrangers with cheery, bright yellow flower clusters that last for months. When each flower sets a purple berry they look like grape clusters. The edible berries make good jelly, too. There are 70 varieties of mahonia including our own native Oregon Grape which grows in the understory of Douglas fir forests. Mahonia aquifolium is resistant to summer drought, tolerates poor soil and doesn’t create a lot of leaf litter.

Other winter blooming plants include euryops, witch hazel, edgeworthia, michelia, grevillea and camellia, of course. Enjoy color in the garden regardless of what Mother Nature brings this winter.

February in the Garden

I’m waiting patiently for the buds on my pink flowering currant to start lengthening a bit more. I wasn’t counting on the recent snow and cold snap but the buds are showing color and are doing fine. Although still small at this stage I’ve assured my hummingbird population that they’re on their way. When I was out pruning last week I didn’t touch this plant otherwise I’d have cut off all those potential flower clusters loaded with nectar. This is what I did do in my garden.

To stimulate new growth I trimmed woody evergreen shrubs like abelia and loropetalum. The Mexican bush sage and artemisia were cut to within a few inches of the ground. I don’t use this approach on lavender or ceanothus, though. Lightly prune those after blooming later in the season and don’t cut back to bare wood inside the plant.

Between rain storms I’ll prune my fuchsias back by a third and remove dead, crossing branches and interior twiggy growth. The hanging fuchsias will be cut back to the pot rim. Fuchsias bloom on new wood so even if your plants didn’t lose all their leaves cut them back.

I cut back all the hydrangeas stems that bloomed last year and will apply a soil acidifier soon as I want the flowers as blue as I can get. Although aluminum sulfate is the traditional favorite for quickly acidifying soil it’s not as kind to beneficial soil microorganisms. Coffee grounds, pine needles, peat moss and cottonseed meal are better for your soil.

Don’t prune spring flowering shrubs like lilac, weigela and spirea or flowering trees such as cherry, plum and crabapple now. These and plants with buds like rhododendron, azalea and camellia should be pruned after they flower. You can cut some branches while they are blooming to bring into the house for bouquets.

Even if you have already pruned your roses be sure to remove old leaves still clinging to the plant. Those will most likely develop fungal spots and diseases later if you don’t. Rake up any debris beneath the plant and discard to eliminate overwintering fungus spores

Roses are super forgiving and you can trim them up again using the following guidelines. The goal is to produce lots of roses not just a few of exhibition size. Aim for a vase-shaped bush with an open center.

Prune old garden roses that bloom once in the spring after flowering. Climbing roses require little pruning. 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 cause the cane to flower along its complete length for a beautiful spring display.

Wait to prune back perennials that may have their new foliage damaged in a late frost. Same goes for shrubs that might have gotten hit by frost. That damaged foliage can protect the plant from further frost damage. Mid-March is the estimated date of hard frost in our area or at least it used to be. We gardeners are always betting Mother Nature will go our way and our efforts will not have gone in vain.

Prune fruit, nut, shade trees and deciduous vines like clematis.

Cut back ornamental grasses if you live where you rarely get frost. I’m pruning California fuchsia, salvia ‘Bee’s Bliss’ and hummingbird sage now. They look okay but I want the encourage new, compact growth.

And now I’m making myself a cup of tea and watching the chipmunk action in my garden. All of nature is getting ready for spring.

How to Control Pests & Diseases

I love it when a nice reader takes the time to call me to suggest a topic they’d like to see me write about or remind them what needs to be done at a certain time of year. Take Helen, who lives in Spring Lakes in Scotts Valley, for instance. Helen told me she grows tomatoes in the summer and has 4 fruit trees including a satsuma plum, an espaliered apple and a tangerine. Helen battles peach leaf curl on her plum and coddling moth larvae inside her apples and would like to know exactly what to use and when to control these problems. So this column is for you, Helen.

Spray dormant fruit trees now for fungal and insect control. Coddling moth control is in March or April.

I know we’ve had a lot of rain which makes gardening and spraying difficult. You can prevent or control many diseases and overwintering insects by applying a dormant spray this month. This can be the most effective spray of the season. Fungal diseases such as peach leaf curl, fire blight, scab and anthracnose as well as insects including aphids, San Jose scale, bud moth, leaf roller, whitefly larvae, mealybugs and mites can all be controlled.

There are several types of dormant sprays and all three types are considered organic. Lime-Sulfur or copper can be mixed with horticultural oil which smothers overwintering insects and eggs. This spray is good for all fruit trees except apricots which should be sprayed in the fall with copper and this month only with horticultural oil.

Apply dormant spray when the temperature is above 40 degrees. Make sure you cover every nook and cranny of each branch and trunk until the tree is dripping and spray the surrounding soil. Spray only plants that have suffered from pests or disease. Sprays, even organic, can kill beneficial insects as well. Even though they’re organic, dormant sprays can be irritating to skin and eyes, Wear long sleeves and gloves and eye protection.

Spinosad has been shown to suppress fungal diseases. Do this when the buds swell but before they open. Do not spray 36 hours before rain in predicted. Be sure to spray the ground around each tree.

Coddling moth control requires a different approach. The larvae of this particular moth is one of the few caterpillars that are likely to be found inside pear or apples. University of California Integrated Pest Management website has complete information about controlling this pest.

The website is http://ipm.ucanr.edu/PMG/PESTNOTES/pn7412.html

The bottom line for coddling moth control is the timing of insecticide spray applications, especially with newer, less toxic pesticides like spinosad. The coddling moth overwinters as full grown larvae within thick silken cocoons under loose scales of bark and in soil or debris around the base of the tree. The larvae emerge as adult moths mid-March to early April. To be effective your spray application must be timed for when when they are active.

Starting three to four weeks after bloom, check fruit at least twice a week looking for the first “stings” or any mounds of reddish-brown frass. If you scrape the frass away you will see the tiny entry hole where the newly hatched larvae has just entered the fruit. Spray the tree as soon as you see the first sting after removing any fruit with stings as the insecticide won’t kill any larvae that have already entered the fruit. Coddling moths can have three or four generations per year.

According to the website, for most backyard situations, the best course of action might be to combine a variety of non chemical methods and accept the presence of some wormy fruit. Be sure to cut out the damaged portions because they might contain toxins generated by mold.

Oh and by the way, Helen told me she is 88 years young so if Helen can do it, you can too.