What to do in the garden in April in zone 5
Average last frost date is April 15 in zone 5
- Apply dormant oil An application of dormant oil to shrubs and trees early in the month will kill most insect eggs. But this MUST be done while plants are dormant and air temperature will be above freezing for at least 24 hours.
- Plant bare root trees Bare root trees, shrubs and roses should be planted as soon as the soil is thawed and dried, usually in early April but sometimes even in March.
- Fertilize evergreens If you haven’t done it yet, pound in evergreen fertilizer stakes or apply a slow release granular fertilizer.
- Fertilize trees and shrubs If you haven’t done it yet, fertilize shrubs and trees.
- Fertilize bulbs Spring blooming bulbs should be fertilized in March or early April.
- Plant perennial seeds Seed can be sown for frost tolerant perennials as soon as the soil has thawed, dried, and begun to warm up. Some seeds however will not germinate until the soil is quite warm, so check directions on your seed pack.
- Plant bulbs Plant summer and fall flowering bulbs as soon as the soil has warmed.
- Prep the beds When the soil has thawed and dried and begins to warm up, usually in March, you can remove winter mulch. Work compost or leaf mold into the top layer of the soil.
- Make new beds Add new garden beds now while you have time.
- Sort tubers Sort through stored tubers, roots and bulbs for dahlias, cannas, glads and begonias if you haven’t done it yet. Dispose of anything that has shriveled or decayed.
- Prune trees and shrubs If you didn’t get it done in March, prune trees, fruit trees and shrubs. Don’t prune any spring flowering shrubs and trees, as the buds have already formed. Prune trees but not oaks, elm or walnut. Prune off any limbs damaged over winter.
- Prune roses Early in April (usually in late March) before growth begins, prune dead, broken and wayward branches from hybrid tea, grandiflora and floribunda roses. Cut back to about 6 inches tall When the forsythia blooms, just ahead of dandelions blooming and lilac leaves appearing, it is time to prune roses. Apply a slow release granular fertilizer.
- Tune up the mower Beat the rush and take it in early in the month if you didn’t get it in in March.
- Clean tools Clean and sharpen shovels, hoes and pruners.
- Check hoses Check hoses for leaks and sprinklers for cracks or damage.
- Check stock Check stock of all gardening necessities such as hand tools, fertilizers, rose and fruit tree sprays, and make a list of what you need
- Clean up Finish any perennial cleanup and removal of winter mulch.
- Plant cool season annuals Plant cool season annuals like pansies as soon as the ground has thawed and dried, usually by the end of March or first of April.
- Harden off seedlings Seedlings started earlier in the year can be set out early in the month on warm sunny days to harden them off. The process is long, setting them out each day for longer periods of time until they are strong enough to be out all day and over night. You may be able to start this process in March.
- Plant hardy annuals Usually by the first of April you can plant the hardy annuals such as geraniums and even petunias. A light frost usually does them no harm but a freeze will. Don’t rush to plant, if it is not warm enough not much will happen anyway. But window box soil warms up quickly and stays warm next to the house, so your hardy annuals will get an early start establishing roots. And containers or hanging baskets are easily moved into the garage if a freeze or hard frost is expected.
- Transplant seedlings Transplant any annual, perennial or vegetable seedlings into the garden beds after the last frost date.
- Divide perennials As soon as the ground has thawed and dried, you can divide and move perennials. Do not divide the very early spring bloomers such as bleeding heart until after blooming or in fall.
- Clean up perennial grass Cut back the dead top growth of perennials and perennial grasses. Leave about 3 or 4 inches of stems that will help keep hungry rabbits out of the new growth and keep you from stepping on them.
- Clean up Check perennials for new growth. Peak under the mulch and if growth is well underway you can remove the mulch. Don’t rush this! If nights are still freezing, leave the mulch in place until nights are consistently above freezing. Many years you will have done this already in March, but sometimes not until April.
- Stake plants Stake tall plants that need support and protection from wind before they get to big to confine.
- Transplant Move shrubs and trees after the soil thaws out and dries up, before new growth begins, and the weather is cool. Transplant shock will be minimized.
- Soil test Test the soil in your lawn and gardens so you know if lime or other additives and nutrients will be necessary before the growing season starts.
- Visit garden centers See what’s new this year before you start buying and planting.
- Apply Aluminum Sulphate The blue Hydrangeas should be treated with Aluminum Sulphate the first of April to keep them blue.
- Fertilize the lawn Depending on weather patterns, this could be March or April. After the first mowing, apply fertilizer. Pre-emergent for crabgrass should be included if necessary. Crabgrass seed generally germinates after the soil temperature has reached 50 degrees, and requires about 5 consecutive days of 50 degree soil temperature. When you see the first dandelion bloom, it is time to apply crabgrass control. If you plan to do spring seeding, crabgrass control may prevent germination of the grass seed unless you “stir up the soil” first to break the barrier.
- Preen Apply Preen to garden beds to prevent weeds if you haven’t already.
- Aerate the lawn Every few years the lawn should be aerated. De-thatching should wait until late summer or early fall.
- Heat up the compost If the compost isn’t ready yet but is not heating up, add green plant material such as grass clippings or fruit and vegetable waste, or add a shovel full of manure.
- Deadhead Snip or shear off only the dead flower heads of spring blooming bulbs. Do not cut back the foliage until it has withered and yellowed.
- Plant annuals By the last frost date you can plant all your annuals or annual seeds. Depending on the year, a cold April can bring late light frosts, which can harm the most tender annuals such as impatiens.
- Mulch Apply a 2-4” layer of mulch on your planting beds to inhibit weeds and retain soil moisture.
- Plant container grown shrubs and trees By end of March or early April, container grown trees, evergreens and shrubs can be planted.
- Prepare potted shrubs and trees Every few years, potted trees and shrubs should be repotted and root pruned. Top dress each year before growth begins.
- Put out a raingauge Take the guesswork out of how much water your plants are getting.
- Spray roses for insects Tea roses, foribunda and grandiflora roses should be treated for insects. Try organic products such as insecticidal soaps, Neem Oil and Remedy fungicide.
- Check for insects Keep an eye on your plants for insects that may be causing damage. Do not indiscriminately spray insects, as many are beneficial. Even those that cause visual damage may not necessarily be harming the plant. Check with your local garden center or extension service to properly identify and treat for insects. Routinely spraying them off with a garden hose or applying insecticidal soap is often the best course of action. Or use a water bottle with a small holed tip on it that will produce a strong stream. Aphids is a common problem. Although they generally do not do permanent damage, they can inhibit growth and weaken the plant.
- Fertilize flowering shrubs Apply a liquid or slow release granular fertilizer to spring blooming shrubs after the flowering is complete.
- Drink water and wear sunscreen!
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