March Gardening

If you mulched your garden heavily before winter, you might consider removing some of it now, but not all of it. A thick layer of mulch can slow soil warming and delay plant growth. If you used compost as your mulch, it can be dug in unless it will significantly disturb the root systems of neighboring plants. If you used bark or similar organic matter, it’s best to compost it before digging it in. If you did not mulch before winter, this is a good time to add a light layer of compost to your soil. Remember, mulch should not be piled up against the trunk of a tree or shrub.

Slugs and cutworms can cause considerable damage during this time of year, so keep an eye out if you have susceptible crops such as lettuce and other greens. Aphids can appear out of nowhere in March and could start doing damage to many of your crops and ornamentals. These pests can be controlled with appropriate baits or sprays, just be aware that they breed and spread fast.

• Learn more about slug control
• Learn more about cutworm control
• Learn more about aphid control

There are plenty of vibrant, spring options ready for you now that spring is arriving, though the full selection of summer bloomers are not quite here. Pansies have been with us all winter and are still looking great, but now you can start adding to the list with blooming bulbs, Anemone, Ranunculus, snapdragons, Alyssum, and more. By the end of March, we almost always have geraniums, fuchsias, and other hanging basket plants. As for new perennial availability, look for candytuft, rock cress, and creeping phlox—all are in bloom and ready for your garden. The evergreen perennials have been in full swing with good availability on hellebores, coral bells, rosemary, lavender, and more. Hellebores especially steal the show in February and March.

See all that new growth starting to form in your perennial beds? Now is the time to get out the old plant food. If you use granular foods, it is a great time to start regular applications. If you prefer water-soluble fertilizers, you might consider waiting until somewhat warmer and dryer weather.

March is often an acceptable time for dividing and moving perennials. If you have not done so and prefer a tidy garden, remove dead matter on your perennials. Cut back any ornamental grasses that are dead looking and brown. Do not cut these to the soil line; leave a tuft to ensure better regrowth.

We’ll soon be stocked with bulbs—including begonias, lilies, dahlias, and many more!

March marks the beginning of tree and shrub planting season, and our selection will grow throughout the month. Roses and fruits are fully stocked at both of our locations. As the plants flush out their new growth, fertilizing can be started on both recent and older plantings. Roses can be pruned in March if they were not done in February (the sooner the better at this point). If you do not want your pines to get bigger, prune the candles off. Hedges can be sheared now if they are overgrown after last year.

Early flowering shrubs can be pruned after the flowers have faded. Tree pruning should have already been done, or delayed until summer in some cases. For disease-susceptible plants, start watching for the first signs of infection on new growth. Once the leaves have formed, it is too late for dormant sprays, but there are in-season pesticides that can help an emerging problem. It’s easier to control a problem as it develops, rather than when it’s affecting your entire plant.

Feel free to plant most greens and cold crops—like broccoli, cauliflower, etc.—but be ready with a frost blanket for any extra cold nights. Many root crops can be planted now, including onions, potatoes, radishes, garlic, and shallots. When planting root crops, be sure the soil has a fair amount of organic matter and few to no rocks. If you haven’t already planted them, peas can be started in March as well. Peas like it cool, so waiting too long can reduce your chances of a good crop. Unfortunately, it is not yet time to plant most “fruiting” vegetables—such as tomatoes, peppers, or squash. You’ll also need to hold off planting your basil outside as well, although it can be started in heated greenhouses, or possibly in your home.

If you do choose to start seeds in the house to get a jump on summer, March to April is often good timing. Most seed packets will note the number of weeks that the seeds need to be started indoors prior to the final frost of the season, so it’s important to plan accordingly. Our final frost of the season can vary quite a bit from year to year, but April 15th is a good, average estimate, and frost is pretty unlikely after May 15th. When starting seeds inside, please remember that most crops prefer full sun and won’t be getting it, and while grow lights can help immensely, a bright south or possibly west window will often work just as well.

Now is a good time for a first lawn feeding, especially if you’re using an organic, granular fertilizer. If you prefer a synthetic food, make sure there is a spell of mostly dry weather ahead to avoid runoff, though you do want to irrigate once after application. If you have not done so in the last year, you can apply some horticultural lime.

April is often one of the best times to add more seed to your lawn, but March can work if the weather is fair. This is recommended for thin or patchy lawns. If you have a thick layer of thatch, you can rake it out now. Moss control products can be applied now if you have not done so already. Watch for the first appearance of weeds—every one that you remove before it flowers is a generation of them that won’t be growing later. Remember, most herbicides do not work in cool weather, so you are looking at doing some hand weeding.

Read more about lawn care.

Spring is the best time for repotting houseplants, so it’s time to start thinking about potting up anything that needs it. You can tell that your houseplant needs a bigger pot when the soil dries out more rapidly than usual or when roots are protruding from the drainage holes. Always use fresh potting soil and loosen the root ball if it’s wound up. When going up in pot size, only go one to two inches larger in depth and/or width. Always water your plants after repotting. Keep in mind that overwatering can still be a problem, as the days are often still quite cloudy. This is especially true of any recently up-potted plants. If you have plants that are particularly sensitive to overwatering, waiting to repot later in spring is an excellent idea.