The roots are coming out of the bottom of the pot of this primrose, indicating it’s time to repot. Photo by Tom Atwell

Once the primrose is out of the pot, you can see the roots are a little crowded. Photo by Tom Atwell

The primrose is now centered in its new pot. Photo by Tom Atwell

This is the time amateur gardeners in Maine get antsy. Spring is around the corner, but it’s not here. It’s too early to start vegetable and annual-flower seedlings indoors. The plants would get too tall and leggy before it is warm enough to put them outdoors.

So turn your attention to houseplants. Late winter/early spring is the ideal time to repot them. They’ll have time to acclimate to their new conditions before the temperatures rise, the sunlight increases, and they need to spend their energy on summertime growth.

Not every houseplant will need your attention. Some grow faster than others, their roots as well as their stems and leaves. Are the roots growing out through the pot’s drainage hole? Are they pushing the plant out of the pot? Is the soil drying out more quickly between waterings than it used to? As you water, does most of the water go right through the pot and out the drainage hole?

Any of those conditions mean it is time for repotting.

Before you start, make sure the soil in the existing pot is at least moist. It doesn’t have to be drenched, but will be easier work if it has some moisture.

Next, decide how large you want the plant to be. If you are happy with its current size, pull the plant out of its pot and trim the roots with a sharp knife and gardening scissors. Don’t go wild and cut the roots in half, but you can trim about a quarter of the roots without harming the plant. Of course, you’re using a sterile knife and scissors.

If the root ends are pushing up against and going around the inside edge of the pot, you must trim the roots, making sure to leave the thick parts from which the stems and foliage grow. Even if you’re moving the plant to a larger pot and aren’t trimming the roots, gently loosen the roots away from the main root ball so the new soil can get in between the root ends.

Unless the plant is huge, the new pot should be no more than 2 inches wider in diameter than the pot you’re replacing. With too much soil, the pot will hold more water than the plant needs and be prone to tipping over.

The choice of pot is up to you. Whatever you use, though, it must have a drainage hole. Plastic and metal are fine. Clay, which is traditional, may be necessary if you’re repotting a tall or wide plant, as the weight of the clay pot will keep the big plant from tipping over. Clean the pot thoroughly by scrubbing it with a pot scrubber. Soak any new clay pots overnight before you use them. Otherwise, the pot will soak up water and any nutrients you add to the soil, which are meant for the plant, not the pot.

Do not use soil from your garden, and not just because your garden is probably frozen now. Outdoor soil may have diseases or insects or worms. Any commercial potting mix from your local nursery will do, but I like Coast of Maine because it’s local. Before you add the soil to the pot, put pebbles, pieces of broken clay pots or window screening, or paper towels over the drainage hole to prevent the potting soil from draining out.

Place the plant in the new pot, with the level of the previous soil about an inch below the top of the new pot. Slowly add slightly damp potting mix, making sure it goes to the bottom of the plant, even under the plant’s roots. You can use your fingers, a chopstick or a pencil to push the soil down, holding onto the plant so it stays centered.

Water thoroughly, then check the plant regularly because, at first, it may dry out more quickly than it did in its old pot.

Tom Atwell is a freelance writer gardening in Cape Elizabeth. He can be contacted at: tomatwell@me.com.