|By Dave Heinen of Heinen Landscape & Irrigation
Kansas City Gardener
While it’s a little too early to begin planting annuals, April offers a great time to prepare our landscapes for new plantings and fresh growth. For starters, we can begin pruning damaged trees and shrubs, clean away debris, have soil tested and analyzed, apply a preemergent, add soil amendments and complete the process by adding a healthy dose of mulch.
Over the winter, the weight of ice and snow may have damaged plant material. If left unattended these plants, trees and shrubs could become diseased, die, or may give you unwanted growth resulting in a plant that is distorted. Pruning these damaged branches will rejuvenate the plant.
Take time to identify the types of shrubs and trees under your care. We’ve all seen trees and shrubs pruned the wrong way. We notice these very quickly. If unsure about the type of plant material in your yard or where to make the cuts, contact a landscape professional.
Other forms of pruning include heading back shrubs to retain size and compactness. You can also rejuvenate some plants by cutting them all the way down to the ground and removing the older canes on multi-stem shrubs. The goal on most plant material should be to keep the inside open to let sunlight penetrate to the middle and invigorate new growth.
Pay special attention to flowering shrubs. Flowering shrubs like forsythia and others need pruning just after they have bloomed to spur new growth and to keep the size of the plant at a manageable level. You will lose a majority of the flowers next season if you prune too late after blooming.
Next, clean the debris clogging your beds. Removing debris can prevent the spread of some plant diseases. For example, if rose plants had black spots last season that caused the leaves to fall off, these dead and diseased leaves need to be removed. Otherwise, you risk re-infecting your plants with the same disease this year.
After pruning and cleaning away debris, you can easily see any weeds needing pulling. You may also want to add a preemergent to your beds. Preemergent herbicides prevent germinating weeds and broadleaf weeds from establishing. These herbicides control annual grass weeds by inhibiting cell division in the young root system. However, preemergents do not kill already established weeds. Contact your local garden center or landscape contractor to learn more about the kinds of preemergent chemicals available and how to use and apply them.
Before planting, think about your soil composition. Plants receive six essential macronutrients from the soil. For a nominal fee, the Kansas State University Soil Testing Laboratory can perform soil tests and analysis to estimate the nutrient-supplying power of your soil. Contact the Johnson County K-State Research & Extension Office in Olathe to learn more at (913) 764-6300. Allow two to three weeks to process your lawn/garden soil samples. Once analyzed, you will know more about what to add to your soil to give your plants the best possible environment.
While waiting for your sample results, use the time to incorporate compost mixture into your soil. Avoid adding compost high in fresh or green woody particles because this will lead to a depletion of nitrogen due to the microbes using it to help break down the woody particles. Now’s also a good time to add a tree and shrub fertilizer to help boost the new spring growth and flowering. Be sure to read your labels to find the amounts you need to use.
Also be sure your compost comes from a reputable source and arrives fully decomposed. Steer clear of compost comprised of grass clippings because the clippings often have persistent lawn chemicals that would not benefit your garden. Once you have completed these tasks and incorporated amendments into your garden beds you should be ready to plant your spring annuals.
Only a few more weeks and the plants will be green and displaying their color pallets of flowers for you to enjoy. In the meantime, adding a fresh layer of mulch will help to retard weed growth and retain moisture in the beds.