by Joan Findley-Perls
Average temperatures range from the upper 30’s at night to day me highs around 70 degrees. By the end of April, temperatures have climbed to a range of mid-40’s to mid-70’s. The mean snowfall is one-half inch, and rain is slightly less than that. The average last freeze is April 18th in the Heights, but frost can occur any me through the first week of May in town, especially in the Valley. In the East Mountain area, the average last frost date is around June 1st.
The last of the fruit trees are in bloom: peach, crabapple, cherry, and nectarine. Forsythia, snowball, golden currant, viburnums, and other flowering shrubs are in their glory. The wisteria is in full bloom, and the lilacs have budded. Fragrant hyacinths are blooming, the daffodils are at their peak, and tulips are coming on strong. Spring perennials begin their bloom: Japanese anemone (A. japonica), creeping Phlox (P. subulata), blue flax, and ajuga (a really great groundcover).
April is blossoms. April is late freezes – and usually the loss of the apricot crop. But not always! April is rarely showers. April is the windiest month in Albuquerque.
March’s blooms continue into April and are complemented with rockcress (Arabis alpina), wall flower “Bowles Mauve” (Erysimum linifolium), catmint (Nepeta), cushion spurge (Euphorbia polychroma), creeping baby’s breath (Gypsophila repens), candytu (Iberis sempervirens), Dutch Iris (re culata) and other species Iris, creeping Mahonia (Mahonia repens), Blackfoot daisy (Melampodium leucanthum) and some other varieties, purple Verbena (Verbena canadensis), Palmer Penstemon, western sand cherry (Prunus besseyi), and Oklahoma redbud (Cercis reniformis). Later in the month you may see red valerian, iceplants, hardy geraniums, and red hot poker.
April is hay fever month. It’s not the only one, but it does have the highest pollen count despite efforts by the City fathers to eliminate pollen-rich plants from local nurseries. If you are an allergy sufferer, this is not the ideal time to work in your garden! Try to identify which plants around your home are producing airborne pollens that cause you misery. Consider eliminating them. Follow the pollen count through the city’s web monitor or the newspaper and try to do most of your garden chores on low pollen count days. Check with local nurseries, call the Master Gardener hotline, or use the City’s Guide to Xeriscaping which has a column in the back section for whether a plant is a low, medium, or high pollen producer. It also lists the plants banned from Albuquerque for allergy producing pollens or invasive growth. So check this source out first if you’re prone to pollen allergies. (See the Information Sources section of Albuquerque Master Gardeners Guide for more information on how to get a copy of this free guide).
Plants with large showy flowers rarely cause allergies because they are bee, moth, bird, or butterfly pollinated. It is the wind pollinated flowers which are usually small and inconspicuous that produce the fine, airborne pollens which cause allergies.
Some Albuquerque area and Santa Fe nurseries specialize in unusual plant varieties. Check the nursery listings in the “Plant Sources” section of Albuquerque Master Gardeners Guide.
To Do List
If you have drip irrigation, examine the lines and emitters to be sure everything is working. Go through your drip irrigation replacement parts and take stock. Buy what you need to keep on hand for new plants and to repair what you have. A small plastic box with dividers and a tight lid helps organize everything – like a fishing tackle box. Be sure to keep recent transplants watered and to increase watering frequency as needed to compensate for drying winds.
Prune spring- flowering shrubs as they finish blooming. Cut back enough to leave lots of room for new growth so you will not have to prune them again un l next spring. Finish pruning roses and grapes by April 15th. Crape Myrtle blooms on new growth, so frost damage can be cut away as soon as new growth appears. Cliff roses need 1/3 of the oldest stems removed every fourth year (this is called rejuvenation when you cut the oldest stems). No other pruning is required. Honeysuckle vine should be thinned every third year. Cut Desert and Prairie zinnias to the ground each April. Shear Desert Globemallow (Louis Hamilton) to its hard center. Remove all the chocolate colored flower heads from Fernbush.
This is a good me to prepare the soil for your annuals and vegetables. Remove and discard all weeds and debris. Spread compost and manure and loosen the soil with fork using a prying motion which preserves the soil layers and organisms. Water thoroughly. If you solarized the beds in late February, re-dig them at this time. Avoid walking on wet beds because it causes soil compaction.
Ants & aphids — Ants and aphids go together. When you see ants in plants, you know aphids are present. Ants drive away aphid predators. Control ants in and around the garden, and you’ll increase natural predators. On trees, a band of TanglefootTM-type barrier will help keep ants off the tree, which will allow the natural aphid predators to do their work uninterrupted.
Cypress bark beetle — Watch cypress trees for browning or breaking ps. This is the cypress bark beetle. Since the insect lives on a dying tree elsewhere, treating your tree will have marginal effects. Making sure the trees have sufficient water is the best protection.
Euonymus scale —An organic approach suggests that scales are often well controlled by beneficial predators, except when these natural enemies are disrupted by ants, dust, or use of persistent broad-spectrum insecticides. If scales become too numerous, a well-timed and thorough spray using horticultural (narrow-range) oil applied either during the dormant season or soon after scale crawlers are active in late winter to early summer should provide good control. Provide plants with good growing conditions and proper cultural care; especially appropriate irrigation, so they are more resistant to scale damage. Prune off heavily infested twigs and branches. Consider replacing problem prone plants. Euonymus scale can be treated with systemic insecticides. To monitor treatment or insect progression, blast the plants with water to dislodge old shells.
Fire blight — Fire blight is a disease of pears, apples, hawthorns, and some other members of the rose family. Growing tips turn black and wilt as if scorched by flame. Typically, in our area re blight is a minor problem and may not need treatment. If the damage is widespread, remove all infected plant parts. As you work, clean the pruning equipment between each cut by either wiping the blades with rubbing alcohol or dipping blades into a diluted chlorine bleach solution, (one cup chlorine bleach to one gallon of water.) Or you can spray rubbing alcohol on the blade between cuts and wipe dry.
Grubs — Lawn grub damage is most noticeable now. While the grubs are easily found by digging, they will soon pupate, and insecticides will be almost useless. August is a better treatment time when the new young grubs are more vulnerable. The organic treatment employs the use of Nematodes, microscopic worms that carry bacteria lethal to grubs. Wait until the soil temperature of your lawn is over 55 degrees Fahrenheit and the soil is moist. Nematodes will not harm beneficials such as earthworms, nor are they a danger to humans, pets, or other animals. If your lawn is infested with white grubs, try milky spores, bacteria in granular or powder form. They remain in the soil to kill any future infestation of grubs. The two best times to apply milky spores are spring and fall. Like nematodes, milky spores are not harmful to beneficial insects such as honeybees, nor will they harm humans, pets, or other animals.
Powdery Mildew — Mildew rears its ugly head on some roses, lilacs, and some vegetables. The presence of these fungi indicates warm moist conditions exist, so your first step should be to reduce the amount of water, the frequency of watering, or the time of day it’s applied. The second step is to get more air circulation around the infected plants. Try not to use overhead watering and do water early in the day so the sun can dry the leaves. Other treatments run from using fungicides to removing the most mildew-prone plants. You might start with dusting the plants with sulfur at first sign of mildew to prevent its spread. Never apply sulfur when the temperature is expected to get too high. Sulfur treatment can be done in early spring but is not usually recommended in late spring or summer, because of possible damage to plants if temperatures go above 90 degrees. Diluted whole milk works with some pants.
Tent caterpillars—Tent caterpillars may appear in several different tree species. The tents are usually webbed close to the crotches of stems and branches. Introducing natural enemies in your garden and also providing good bird habitat can reduce the problem naturally. Chemical treatment requires tearing open the tent before spraying. Since most caterpillars pupate and leave, the problem may be self-limiting. Pruning out and burning a affected branch tips is also effective.
Watering needs increase with sunnier and warmer days. Fertilize with half the recommended amount twice a month. Be sure to watch small transplants – NEITHER overwater nor allow the soil to get overly dry. Keep plants that you are growing for transplanting in a sunny place in indirect light or continue to grow under artificial light. Read a houseplant book to learn about your plants and what they need (see the Information Sources in the Albuquerque Master Gardeners Guide for ideas).
Do you know how to plant tomatoes? You might want to try early planting -- after April 15th, if you have a sheltered area, a warmer than average micro-climate, or you want to try using a “wall-o-water” (mini greenhouse). Prepare soil by digging and amending it with compost in early April. Dig a hole 12-18” deep and 12-18” wide. Amend this with granular slow-release fertilizer (use compost combined with fish or kelp meal for an organic approach) and 1⁄2 c. Epsom salts. Back fill the hole with several inches of soil. Choose a 12” or taller plant, remove the lower leaves, and lay the plant in the hole with some of the stem in the hole. Back fill, covering most of the stem, and water thoroughly. Protect from frost as needed. Your tomato plant will produce roots all along the buried stem creating a stronger stem and root system and you get a thrill from being able to tell your friends you planted early. Depending upon the weather, you should have tomatoes several weeks earlier than if you plant in mid – to late May. You’ll also have fewer insect problems.
This is an excerpt from the calendar published by the Albuquerque Master Gardeners. Visit their website for a schedule of classes and events!