Planting Season Has Begun

By Portland Nursery

Assuming your ground is workable, March is first planting time for most of us. If you have water-logged clay soil, you might want to cover it with plastic or wait for a dry spell before digging. Otherwise, start getting those hardy plants in the ground. The danger of frost has not yet passed so you’ll still need to protect your tender plants that will not survive a hard frost—including newly planted vegetables and annuals. Somewhat sadly, it’s still a little too early for truly warm season crops.

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 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 that 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 quickly.

Perennials and Annuals

There are plenty of vibrant, spring options ready including pansies,  blooming bulbs, anemones, ranunculus, snapdragons, alyssum, and more. By the end of March geraniums, fuchsias and other hanging basket plants should be ready. As for new perennial availability, look for candytuft, rock cress and creeping phlox. Evergreen perennials with good availability include hellebores, coral bells, rosemary, lavender and more. 

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 awhile or at least until periods of somewhat warm and dry weather. March is often an acceptable time for dividing and moving perennials. If you have not done so, remove dead matter on your perennials if you prefer a tidy look. 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.

Begonias, lilies, dahlias and many others are summer bloomers that can be bought now and grown yourself. This is significantly less expensive than buying grown plants later in the season.

Trees, Shrubs and Fruit

March marks the beginning of tree and shrub planting season. Roses and fruits are available and 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 (new growth) off. Hedges can be sheared now if they are overgrown after last year.

Early flowering shrubs can be pruned after the flowers have faded. Any pruning of trees should probably 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 to dormant spray, 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—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, peas can be started in March, as well. Peas like it cool, so waiting too long can reduce the chances of you getting 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. It’s still too early for it, but it can be started in heated greenhouses or possibly in the house.

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 15 is a good, average estimate and frost is pretty unlikely after May 15. When starting seeds inside, 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. Also, if the time you were planning on placing the starts outside turns out to be unseasonably cold, you might have to delay the planting (remember any rainy Junes?) and the plants might get a little leggy.

Lawn Care

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. Note that most herbicides do not work in cool weather, so you will be looking at doing some hand weeding.

Photo by Kris McDowell

Planting Season Has Begun

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