Today I divided an ornamental grass plant that had become too large and dense and was threatening to take over. I gave one third to my best gardening pal, Linda, and moved another third to a spot beside the deck on her advice, leaving the last part in its original position. The early spring and fall are generally considered the best times of year to divide perennials; in the fall they've done most of their growing for the season and their blooms have withered and gone, but there is still time for their roots to take hold before the ground freezes.
In general, if you've got a large bed of perennials such as black-eyed susans or echinecea, it's easy to simply take a spade, dig out part of it and move it somewhere else without much fuss. Dig around the roots enough so they've got earth still packed around them. You can cut cleanly through the roots with the spade and dig up as much as you want. That kind of perennial that sends out new shoots from their underground root system can sprawl incredibly in a few seasons so it's a good idea to keep them in check before they crowd out all the other plants.
Here's how to transplant, divide and replant a clump-like plant that's grown too big:
1) Water the plant to be divided (or a new plant about to be transplanted from a pot) very well, preferably earlier in the day or the day before. If you forget to do this, make sure you water it well anyway, and wait at least a few minutes or as long as you can.
2) When transplanting (or planting a new plant) to a new site, dig a hole a few inches deeper and wider than the root ball (for shrubs and larger plants, a good 6-12 inches deeper), amend the soil with a shovelful of compost or well-composted manure or leaf mould and some bone meal (which encourages root growth); mix these in the bottom of the hole with some of the soil and wet it with some diluted fish fertilizer if you have any. Prepare the new hole before you dig out the plant destined for division. The less time the plant spends out of its hole, the better.
3) Now, dig out the whole plant (this is what I did today with the grass plant, and it wasn't too bad since the roots weren't deep). Starting a few inches away from the base of the plant and up to 12 inches for a larger plant, dig with a sharp spade and deep enough to get most of the roots. The roots you can't dig out should be cut with a sharp pair of clippers, rather than just yanked and torn, which does more damage to the plant.
4) With the plant on the ground in front of you, take two pitch forks (or try it with one if you don't have two) and try to ease the plant apart at the point you've marked for division. If the root system is too dense (such was the case with my ornamental grass plant) use pruners to cut the roots. At the same time, cut out any dead or sickly looking branches to thin out the whole plant.
5) Place the root ball in the hole so that the base of the plant is slightly lower than the ground around it so that water will flow towards the plant and not away from it.
6) Fill the space around the plant with the remaining soil, tamp down and water very well. This is an important step because the water will help the soil fill in any air pockets around the roots as well as encouraging new growth. Keep watering more often than usual for a couple of weeks until the plant is well established.
That is a basic method for planting/replanting that works very well. If you're in a hurry or just plain lazy, you can usually dig out parts of plants without pulling out the whole thing, but a lot of plants benefit from the process above. Another point to remember is that plants have different soil and light needs and it's a good idea to check into their individual requirements before you plant. Here is a partial list of plants that can be transplanted right now or in the next couple of weeks:
Irises: dig out the whole plant using a pitch fork or spade, cut between the bulbous parts (the rhizomes) from which the leaves are springing, then replant the parts, leaving most of the bulbous parts showing but burying the long stringy roots, not forgetting the compost and bone meal, water in as usual.
Peonies: they're a bit finicky to transplant and may not flower much for a year or so, but if you're putting them in a better spot (sun vs. shade for instance), they'll thank you for it with wonderful growth and flowers sooner or later.
Herbs like oregano, thyme, mint, lavender
Shrubs and trees: the instructions are basically the same as for regular perennials but the hole is bigger! Check for specific instructions for individual specimens and make sure you plan ahead to find a spot that fits the mature plant, some shrubs grow much larger than you imagine!
Once you've finished your hard work, make yourself a cocktail such as the "White Lady" shown in my photo, and relax, you've earned it!
P.S. This is also the time of year to plant your spring-flowering bulbs! I will post something about that next time. I hope this answers your question, AJ! Thanks for posting!
Welcome to The Tranquil Garden
I hope you will enjoy the journey I'm starting today. I welcome all your comments and questions on my blog posts and hope you will find my observations about my garden interesting and possibly helpful. I am not an expert (far from it!), so this will be a learning experience all round. I'm planning to do research when questions come up that I can't answer. Frankly, the only reason I feel qualified to write a blog is because anyone can do it! The reason I chose to blog about gardening is because I love it, and I think it's therapeutic to get one's hands (or gardening gloves) dirty by planting things that with luck, educated guesses and a bit of sun and rain, will grow!