How Often Do You Replant Your Flower Gardens

Break free of tradition — most perennials are fine for transplanting almost any time of the year. Here's how to move your perennial plants without damaging them.

"Why didn't I plant those daffodils beside the doorstep? Now I have to wait until fall to transplant!" The best ideas don't always come to us when we want them to. Those coppery orange daylilies in your summer garden, for instance—they sure are showstoppers, but it's a shame the blue veronicas are way over there. They would be glorious with the daylilies.

We've all done it. No matter how much time we spend figuring out where to plant what, we always make mistakes. We think we have it just right—until the plants come into bloom. Then we wish we'd planted those bright Asiatic lilies behind the cool blue campanulas, or partnered the deep red rose with the pure white Shasta daisies, or put the daffodils right beside the doorstep.

It goes on all season, as plants grow and bloom and show us the error of our ways. Sometimes we're off by a matter of inches, or sometimes many feet. Don't live in regret, though. The next time you think, Why didn't I plant that here instead of there? just dig right in and fix it on the spot. I call it designing with a shovel.

All of these plants, plus many more, can be transplanted in bud or bloom: agastache, artemisia, Asiatic lilies, Monch aster, bee balm, bulbs, Goldsturm black-eyed Susan, cardinal flower, campanulas, thread-leaved coreopsis, daylilies, feverfew, liatris, mums, obedient plant, phlox, coneflower, sedum, Shasta daisy, Siberian iris, veronica, yarrow.

Transplanting Anytime

Sure, you could wait to transplant misplaced perennials and bulbs until fall, when plants are done blooming, or early spring, when they're just getting growing. But why wait? You can move many perennials—anything with fibrous roots—and just about any bulb while they're in bud or even in bloom.

For best results, transplant on a cloudy day if you can so the plant won't lose moisture to the sun from its leaves. If you can't wait for the weather, transplant in late afternoon. That way the plant can begin settling in without being stressed by a day of sun.

Of course, the most important thing you'll need for designing by shovel is something you already have—water. No matter how careful you are when digging, you're going to slice through some roots, and roots bring the plant water. Until they settle themselves in the new spot, the plant won't be able to get enough water to keep it from wilting. The solution? Watering at every step of the way.

Transplanting How-To

Start by giving the plant you intend to move a good drink so it'll be well-hydrated by the time you transplant. Decide exactly where the plant is going to go. Dig that hole, making it a generous size—about 10 inches across and a shovel-blade deep is a good start. You can adjust it later.

Next, fill the hole with water and let it soak in. Fill it again and let it drain again. If the water still disappears within, say, 20 minutes, do it a third time. The soil should be moist, not muddy; this extra moisture ensures that the surrounding soil won't wick away the water from your transplant.

Now you're ready to begin moving operations. Dig all around the plant (or clump of plants, in the case of bulbs), wider and deeper than you think you need to. For bulbs, dig at least 10 inches deep; for other perennials, you may need to go down only 6 to 8 inches or so. I use a drain spade, sold at hardware stores—its longer, narrower blade is perfect for this operation.

Eyeball the size of the root-ball when you lift it, and then gently set the plant back in place. Check your new hole—is it big enough for the roots to fit, and deep enough so the plant will sit at its previous height? If yes, great! If not, adjust the hole. If it's too deep, just put some soil back in the bottom.

"Handle with care" is the motto when transporting the plant. Keep the soil around those roots as intact as you can, and be careful not to break stems or knock off buds. If your plant isn't too big, simply carry it on the blade of your shovel to the new hole, supporting it with one hand. For larger plants, use a wheelbarrow. Slide the root-ball into the new hole, and turn the plant until you're satisfied that its best face is forward. Fill the hole halfway with soil and firm it down.

Next, more watering! Fill the hole with water again, but don't wait for it to drain. Go ahead and finish filling in the hole with soil, and pat it down gently so that you don't squish out all the oxygen, because roots need air as much as water. Supply temporary shade for the first day or two to help prevent wilting. An easy way to do this is to set a lawn chair over the plant.

Think of your new transplant as a bouquet of cut flowers for the first week. It needs extra water until those new root hairs take hold, but water too much and you could drown it. If puddles stay on the surface for more than a few minutes, back off with the hose.

It's amazing how quickly a transplant settles in, even if you move it at the peak of bloom. In as little as two to three days, your plant will look as if it's been there forever—in exactly the right place.