Phenology in the Garden

When daffodils begin to bloom sow sweet peas.

The daffodils are blooming. Will spring be early this year? When will I no longer need to worry about the danger of frost? How much is climate change affecting our natural world? We can all remember years when there is little rain in January and February and it feels like the Bahamas around here. Then there’s this year. Well, I don’t need to tell you about our weather this winter. But what are the plants around here doing? Leafing out early? How about those invasive plants around your yard?
Look to phenology indicators to give you some insight.

Phenology – not to be confused with phrenology which claims that bumps on the head predict mental traits – is the study of key seasonal changes in flowering times, emergence of insects and migration of birds from year to year. When do they occur each year? Phenology is a real science that has many applications. In farming and gardening, phenology is used chiefly for planting times and pest control. Predictions for fire season are based on factors pertaining to weather as well as plant growth. Certain plants give a cue, by blooming or leafing out, that it’s time for certain activities, such as sowing particular crops or insect emergence and pest control. Often the common denominator is the temperature.

Websites like USA National Phenology Network at http://www.usanpn.org/ offer lots of information on the subject. The US Global Change and Research Program released the first 14 indicators of climate change. Among these is the Start of Spring indicator on this website which reflects the accumulation of heat sufficient to initiate leafing and flowering in temperature sensitive plants. Your own observations via Nature’s Notebook will help contribute to this research.

Indicator plants are often used to look for a particular pest and manage it in its most vulnerable stages. They can also be used to time the planting of vegetables, apply fertilizer or prune. Here are some common garden plants and what they indicate:

When dandelions bloom, plant spinach, beets and carrots.

When daffodils begin to bloom, sow peas.
When dandelions bloom, plant spinach, beets and carrots.
When lilac leaves are the size of a mouse’s ear, sow peas, lettuce and other cool-weather crops.
When lilacs are in full bloom, plant beans.
Once lilacs have faded, plants squash and cucumbers.
When apple trees shed their petals, sow corn.
When dogwoods are in full bloom, plant tomatoes, peppers and early corn.
When bearded iris are in bloom, plant peppers and eggplants.
When locust and spirea bloom, plant zinnia and marigolds.

When forsythia and crocus bloom, crabgrass is germinating. When this happens the soil temperature at a depth of 4 inches is 55 degrees. Treat with an organic pre-emergent.
When crocus bloom, prune roses and feed your lawn.
Mexican bean beetle larvae appear when foxglove flowers open.

Record your own observations. Another great site is National Sustainable Agriculture Information Service at http://attra.ncat.org. Sites like these can also help you design orchards for pollination and ripening sequence, design for bee forage plantings, design perennial flower beds and wildflower plantings as well as plantings to attract beneficial insects and enhance natural biological control. How cool is that?

Gardening Tips for the Allergy Sufferer

Several of my friends suffer from allergies nearly year round starting in January. Most of us don’t notice the amount of pollen in the air even when it’s cold but my friends sure do.

Acacias get a bad rap by allergy sufferers.

Everybody blames the Acacia tree for their allergies but they are not the real culprits for the allergy sufferer. Redwood pollen is dispersed at this time of year. Strong winds can cause the yellow redwood “flowers”, which are actually the flowers of the male cone, but boy can they put out the pollen. And because redwoods live in such a narrow band of coast line, there is no allergy shot for those highly affected by them. But back to what you can do in your yard if you suffer from allergies.

Yes, 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.

Redwoods are a major source of pollen.

According to historical records for our area the pollen count is mostly moderate in February. Depending on the weather, www.Pollen.com and www.Pollenlibrary.com show medium high counts only for a few days this month. If you’re an allergy sufferer you don’t need a website to tell you what the count is. Our native red alder is in bloom now and it, along juniper and birch, are the main culprits at this time. Grasses, ragweed and other weeds and most trees bloom and shed pollen in March, April and May. Then comes summer, then fall and with it other problems for the allergy sufferer. To further complicate and make matters worse for the allergy sufferer, climate change is making pollen season longer and more intense. You can’t control what’s growing outside your own yard but here are some tips for what to plant and not plant in your garden.

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 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 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.

We don’t know what’s going to happen rain-wise for us this spring. 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 sneeze-less spring for you allergy sufferers

The February Garden

Wait to prune Flowering Currant until after flowering.

Hopefully these cold mornings will be a thing of the past by the time you read this. My plants were much happier right after the rainsI when nights were mild. ’m waiting patiently for the buds on my pink flowering currant to start showing color. I saw some recently in Felton that were already opening. Mine are still pretty small at this stage but 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. Here are some February tasks that I am doing.

To stimulate new growth trim woody evergreen shrubs like abelia and loropetalum soon. Cut Mexican bush sage and artemisia 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.

Fuchsia ‘Firecracker’

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. A plant is wasting energy on new growth if trimmed later. Let your plants dictate when the time is right. Every garden is different and in microclimates in your own garden temps can vary widely.

My previous hydrangea garden.

Cut back hydrangea stems that bloomed last year and apply a soil acidifier if you want blue flowers. 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, spirea, flowering currants or flowering trees such as cherry, plum and crabapple now. These and evergreens like rhododendrons, azaleas and camellias 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 pruned your roses be sure to remove old leaves still clinging to the plant even if the leaves look okay now. They 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

Wait to prune back perennials that may have their new foliage damaged in a late hard 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 now.

Cut back ornamental grasses if you live where you rarely get frost. When I grew California fuchsia, salvia ‘Bee’s Bliss’ and hummingbird sage I’d prune now to encourage new, compact growth.

And remember to enjoy your time in the garden. It’s only work if you think of it that way.

Bare Root Roses & Pruning

Hot Cocoa was introduced in 2002 but is still a popular selection.

I see some outstanding new rose varieties available for the 2023 season. It won’t come as a surprise that they are all very fragrant and have good disease resistance. So while you’re out in your garden pruning your existing roses consider adding a new one or two now available in barefoot form as they are less expensive than the canned ones. Here are a few that caught my eye.

Heavenly Scented is a traditional hybrid tea rose with both a strong scent and disease resistance. This stunning rose produces 4-5 inch salmon blooms that have a great spicy-fruity fragrance and are good for cutting. Also out this year is Picture Perfect, a bright fuchsia rose with a creamy white reverse. With strong disease resistance and showy fragrant blooms borne on long stems this is another great rose for bouquets.
Or maybe the magenta Sultry Night with touches of blue and a lighter reverse would look stunning in your garden alongside Uptown Girl which is a great beginner’s rose with scalloped coral-pink petals with the look of English roses?

Distant Drum

But what about pruning those existing roses in your garden? First of all remember that roses are super forgiving so just go for it and you can trim them up again later. Here are some tips to get started.

Most of us want our rose bushes to produce lots of roses on a compact shrub and not just a few exhibition size blooms so prune your shrubs moderately. 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 Slant the cut away from the bud to encourage growth outward. Clean pruners after every use to prevent the spread of disease and keep your pruners sharp.

Heirlooms roses such as David Austin, other old antique garden roses, and floribunda roses require less pruning because their open look is part of their charm. Keep this in mind and prune lightly. Old garden roses that bloom once in the spring should be pruned after flowering.

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.

Strike It Rich

It’s best to prune your roses before roses start leafing out or some of their energy will be wasted. Pull 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 s10 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.