How big did your plants grow this year? 2003 seems to have been a year of prolific growth in my garden. Following the long awaited thaw (that most of us have forgotten already…) the plentiful rainfall interspersed with hot sunny periods during this summer certainly played a big part in this respect. Installing rain barrels has proved to be a worthwhile investment at my home. They have provided a steady supply of natural rainwater at the turn of a tap, and they have been invaluable for coping with my many numerous thirsty hanging baskets and containers. I always add a quantity of 20-20-20 water soluable fertilizer to my rain barrels. This saves me a lot of ‘mixing and hauling’.
Now is the time to inspect your garden. Look for plants with flowers that are smaller than normal, clumps of plants with bare, dead centres, or plants where the lower foliage has become sparse. This is a clear indication that these plants are due for a touch of minor plant surgery carried out by division. Dividing your perennials at this time of year will rejuvenate them and invigorate their roots.
Some plants need regular division every two to three years to keep them at a managable size. Another good reason for dividing perennials is to increase their numbers and allow you to have further plants for your garden or to share with friends.
Plants are normally divided at two different times of the year, spring or fall. As a ‘rule of thumb’ spring and summer-blooming plants are best divided in the fall, and fall-blooming plants prosper by being divided in the spring. The plants can then focus their energy on producing new roots and leaves, and will have become fully established when flowering time arrives, thus enabling them to properly concentrate on producing top class blooms.
Between September and October is a good time to divide spring-blooming perennials, depending upon where you live; a good guide is to allow at least four to six weeks before the ground freezes to allow the roots to become re-established. This is an excellent weekend for perennial dividing!
Never divide plants on a hot sunny day. Cloudy and overcast weather is best. If this is not possible, try dividing later in the day and have the new planting holes prepared in advance. Water thoroughly, keeping the soil adequately moist for several weeks afterwards.
Early spring (April through early May) is the best time for spring division, as soon as the growing tips emerge. This will allow sufficient time for the roots to become re-established before the hot dry weather. Spring-divided plants often bloom a little later than normal.
A little preparation before dividing your plants is extremely beneficial. Water the ground thoroughly the day before transplanting and prune back the stems and foliage to make division easier as well as reducing moisture loss.
Lifting and Dividing
If you can manage to dig and lift the entire plant from the soil before dividing it, this by far and away the best method. (If the plant is very big and heavy it may be necessary to chop it into several pieces before moving.). Using a pointed shovel that has been sharpened using an axe file, dig down around the sides and beneath the roots 10-15cm from the edge of the plant, and lift the entire plant from the soil.
You can now start to divide up your plant. Basically there are two different methods of separating your plants, depending upon the type of root system it has. One method is to chop, and the other is to tease the roots apart. Tough, tense roots such as Peonies, Hostas or Daylilies will need to be cut apart with a sharp knife or garden spade – slice away and don’t worry about damaging the roots. Tangled, fibrous roots, such as New England Asters, Monarda and Echinacea can be teased apart by hand or, for large tough clumps, by inserting two garden forks back to back into the centre of the clump and gradually prying the clump apart.
Occasionally it is necessary to take really drastic action with plants that
