Download a printable copy of our APRIL Gardening “To-Do” Checklist.
Gardens need water in the spring, which has been wet so far this year but who knows – drought could settle in any week now. So if the precipitation does let up, do some watering, and the best watering technique (except for watering seeds) is deeply, not frequently. We have more about proper watering techniques here.
- If you are growing plants from seed, don’t oversow. For fine seed, mix it with sand so it is easier to spread over a larger area.
- Don’t start warm weather plants too early. Peppers and basil, and to a lesser extent tomatoes—hate cold weather. Wait until May and a forecast for consistently warm weather before planting these.
- Plant radishes now. They grow in cool weather (the flavor is more mild) and they grow fast–you can harvest the first ones about a month after sowing. They are fun for kids because you get results fast. Some people are known to eat radishes, too.
- Prepare soil for growing summer vegetables by adding organic matter. (Chickity Doo Doo is a favorite of one Behnkes staffer). And weed your asparagus patch if you haven’t done it already (March is the best time to do it.)
Perennials and Flower Borders
- If you didn’t clean-up your borders in March, do it now. (Gotta remove weeds now while they’re still small and haven’t flowered yet.)
- Cut back all ornamental grasses to 6-12″ if you haven’t done it already, and don’t wait any more. It may already be difficult to cut off the dead leaves without also harming the new ones.
- Plant, divide or move perennials – it’s now or never! Okay sure, you can still do it in May, especially planting new ones, but it’s best to get all this jostling around of perennials done before it gets hot, and it gets hot in Maryland soon – certainly by May.
Trees and Shrubs
- Feed roses mid-month and monthly through July, and Rose Tone is a popular choice.
- It’s a terrific time to transplant or plant new trees and shrubs – both the evergreen and the deciduous types.
- Prune back early-blooming shrubs (as desired) that have finished blooming, such as forsythia, quince, witchhazel, winterhazel and wintersweet.
- Prune your late-blooming hydrangeas now, if they need it (to reduce the size). That means H. paniculata types, like ‘Tardiva’ and H. arborescens types like ‘Annabelle.’ Don’t touch your moptop or lacecap hydrangeas, though, or you’ll prune away this year’s blooms.
- Prune your roses if you didn’t do it in March (preferred) and do it SOON. and Miri Talabac says, “A rosarian who used to work here always recommended a dab of Elmer’s glue on the cut cane to discourage borers and prevent cracking from water seepage in freezing weather.”
- Cut back Caryopteris to 8-16 inches or so and butterfly bushes to 15-24 inches.
- After they’ve flowered is the perfect time to prune azaleas, which probably really need it (unless you’re on a regular yearly schedule of maintenance and rejuvenation pruning).
- Watch for tent caterpillars in cherry trees especially, and if you spot one, grab and destroy their tent with a stick. That can mean simply opening it up to the birds, or tossing it into a plastic bag you put out for the trash.
- Watch for viburnum-beetle egg cases and prune them away before the larvae hatch.
- As the soil warms up, it’s a good time to apply organic fertilizers like Holly-tone (for acid-loving plants) and Plant-tone. Another option is to apply a top dressing of compost around the base of the trees or shrubs.
- As fruit trees begin to bud and leaf out, now’s the time for preventative pest and disease spraying to start. Many pesticides/fungicides suitable for edible plants will require multiple applications, and bud-break is the starting point to begin attacking fungal spores and insect eggs before they get settled onto or into your trees. Follow package instructions, since each product is different, as are the correct rates of use for specific trees at different stages of growth.
- April is a great time to seed, over-seed or sod the lawn. (Just be sure you’ve waited the recommended number of weeks since you’ve applied pre-emergent crabgrass killer – or it’ll kill your grass seeds, too.) Experts are often heard recommending over-seeding because it’s probably the MOST needed lawn maintenance job that’s ignored by the MOST homeowners. Having a thick lawn is the BEST way to prevent weeds!
- If your lawn is filled with moss, it needs lime and now’s a good time to apply it.
- If you’ve been feeding your lawn regularly and over-seeding, too, it probably doesn’t need to be fed again until the fall. If your lawn is thin and weedy, it may not be getting enough fertilizer and spring is the second-best time to feed the lawn – with an organic or slow-release fertilizer, or simply a top dressing of compost. Over-fertilization of lawns, especially in the spring, is a HUGE problem for the Chesapeake Bay.
- And now’s a good time to get your lawn mower ready for the season.
For the Critters
- Migrating hummingbirds will reach our area soon, so be sure to clean your feeders and stock up on nectar solution. Remember to only use soap and water to clean the feeder and be sure to clean it regularly during the season to keep your visitors healthy.
- Encourage nesting birds to stay by planting flowers nearby that attract small insects, the necessary diet for baby hummingbirds.
Protection FROM the Critters
- Apply deer repellents now. Deer are switching over from winter food sources to spring summer food sources. If deer ran personals, they would be ISO nice tender hostas, daylilies, and other emerging sprouts. Once they set a trail, they tend to return to the same spot on a regular basis. If you apply repellent now, and they find your plants unpalatable, you’ll have less of a problem later on. Read the label, and remember that most repellents smell…well, repellent. Have mercy on your neighbors and don’t spray on a day when they are going to have windows open or have the boss over for cocktails on the deck.
- Now’s the best time to get a start on controlling slugs, and Sluggo is everyone’s favorite product.
More from DC Master Gardener Barbara Dinsmore
- Be sure to visit McCrillis Gardens in Bethesda. You can picnic there and take your dog on a leash.
- Don’t blow all debris out of your gardens – leave a little bit of stuff for nesting birds.