Wrestle those garden monsters into submission

Every year I take a spring walk through the garden and say to myself, “Hmm, that Bishop’s Weed seems to be getting full of itself. We’ll need to break up that party for sure. Uh-oh, those Iris have totally outgrown their boundaries — again.”

The dividing, cutting back, trimming and mucking about with perennials just never seems to end.

Typically, one divides perennials to propagate the plant; to keep it under control and in its allotted place in the garden or, in some cases to give it new life.

Rhubarb is a good example of the latter. When it gets over grown and crowded it will yield weak, thin stalks, until it nearly dies off altogether. Amazingly, even if it is in an overgrown, weakened state, a drastic division can do wonders.

Rhubarb has thick, woody roots which, in an excessively overgrown state, are so solid they may need to be divided with an ax. Just chop it up into chunks about five inches square, plant the chunks and you’re pretty much good to go. They are best divided in the early spring, but will likely not reward you with incredible growth that first year. The following year, however, they should be giving you some fabulous stalks and lots of jelly material for your trouble.

Ferns also have roots that require this treatment.

Bishop’s Weed, which I know many of you curse on a daily basis, is a root-spreading plant that loves to propagate itself into neighborhoods where it is simply not welcome. In this case, division would most likely be to keep it from losing its manners and taking over the garden. Root spreaders can be a bit tricky to split as any bit of root left in the ground has a propensity to become a new plant.

Bishop’s Weed can be dug up just about any time as long as you remember to dig deep and thoroughly when dividing. Do not spare the earth — it can be replaced, but that root must go. Once out of the ground the pieces can be planted anywhere you like, just plop them in the ground, cover all but a few leaves with earth and ignore. Even if it looks dead this year, it will reappear next spring with a vengeance. If you are dividing to get rid of this happy camper, put it into a garbage bag and throw it away. Even then, I swear it can crawl out and cause trouble when no one is looking.

Other common root spreading perennials are Sedum, Lamb’s Ear and Yarrow.

To create more of a favorite plant, division can be very economical.

One-gallon perennials typically cost between $7 and $12. A clump divided can be worth several plants in some cases, saving you enough money to require a trip to your favorite greenhouse.

If you are frugal, you’ll just enjoy not having to spend any money.

Most perennials like to be divided right now, or as close to now as you can get into the ground.

It looks like it might be a bit of a late spring, so don’t get too excited. Leaving some of the parent plant in the ground, cutting off part of it for division generally works well if you are dividing for the purposes of propagation or to control the size of the mother plant, unless its roots are so crowded they must come out and be pulled apart.

Iris often needs this treatment, as over-crowded roots (rhizomes, in this case) provide thinner leaves and fewer blooms. Digging up the clump, pulling the roots apart and re-planting them is often the only thing to do.

Other common perennials in this category are Hosta, Daylily, Astilbe, Delphiniums, Trollius, and decorative fescues.

If divided early and cleanly, your plants may never know it happened. But be careful of mucking about with some plants. They will never forgive you and could just as likely drop dead to never show up again. In this category are Oriental Poppies, Columbines and Baby’s Breath. If forced to move one of these, as a large plant, proceed cautiously, dig early, and far out around and under the plants root system. Never dig them once they have begun to grow. In the case of all three of these plants, digging up tiny seedlings and placing them where you want new plants is a good idea, but use the same rules — dig early and dig deep.

Sally Koppenberg is a garden and food designer. She is the owner of Stonehill Gardens and The Red Beet, a nursery and catering companies specializing in Alaska Grown foods, trees, shrubs, perennials and native plants. Contact her at Stonehill@gci.net.