Care Through the Year-Summer
In the summer, the only thing things that have to be done are fertilizing in the early part of the summer (see the previous Fertilizer section), “deadheading,” and diseased or dead foliage, staking, and watering and dividing.
"Deadheading"
Deadheading is removing spent flowers from the plant to prevent the formation of seed pods. You want to stop the plant from forming these seed pods because if you let them form, it will weaken the plant, shorten the blooming time, and shorten the life of the plant In addition to helping your plants remain vigorous, deadheading will also encourage your perennials to rebloom. To deadhead, all you basically have to do is use your pruners and snip off all the faded and dead flowers. When it is possible, cut the dead flower stem to ground level, if not cut off the stem just below the top leaves.
Removing Dead or Diseased Foliage
Once again, this is merely a matter of common sense, if you see part of a plant that is yellow and covered with all kinds of nasty bugs, use your pruners and cut it off! Removing the dead and diseased foliage will make your perennial and your whole garden more healthy. Keeping diseased foliage around the garden is bad news for your plants because it will only attract more harmful insects.
Staking
For a natural-looking, inexpensive-in fact free-way of staking your perennials, use the upper branches of tall trees, such as elm or birch. Or you can use twiggy brush-wood. When the perennials start to send up shoots and the soil is moist and easily penetrateable, encircle the group of plants that will need staking with the twigs and cut them so they face each other and form a “roof” over the plants. The foliage will grow through the branches and mask them while being supported by them. This is the cheapest most natural-looking way of staking, just make sure the branches are strong enough to support the weight of the plants when they grow.
Watering
A word about watering. Watering less but more thoroughly is better then watering constantly without soaking your plants completely. Water your perennials once or twice a week, but water them very deeply. If it has rained intermittently and you are unsure that your garden needs to be watered, put your finger an inch or two deep in the soil, if it is dry, chances are that it is in need of a good, long soaking. Try to water them as early as possible. If you water them during the day and wet the leaves, they may burn in the sun. If you water them in the evening, they may not dry out and get a fungus.
Dividing
Divide your perennials in the early part of the summer, when they are a few inches high, before they have really begun to grow. If you miss this period, divide them in the fall. If you divide them in the hot part of the summer, chances are you will forget one of their three-a-day waterings and they will die. There are two basic ways to approach the division of your perennials. The first is to dig the entire clump out with your shovel and to cut the clump into pieces-each becoming a new plant.
The second approach is to remove sections or “babies” growing alongside the plant while the mother plant remains intact.
When you are using the first approach, be careful to dig deep enough as to get all the roots out. If the roots are not too intertwined, then attempt to pull them apart by hand. If this does not work, use your pitchfork to try to separate them. If this still does not work, use your shovel to break the plant into pieces. Use your pruners and cut off any part of the roots that are unhealthy. When you replant divisions, remember to keep them very well watered. Any part of the plant that has ceased to bloom and has become “woody,” discard, and plant one of the outer divisions in its place.
Care Through the Year-Fall
In the fall, the only things you have to do are cut your perennials back for the winter and mulch them.
Cutting Your Plants Down for the Year
Let your plants die down naturally. After the first few frosts, cut off the dead stems. Leave about 4 inches of the stem to hold the snow to provide additional insulation. It is not carved in stone that you have to thoroughly cut everything down; for example, you may want to leave some stalks for winter decoration. Just keep in mind that whatever you neglect to cut down after the first few frosts, will have to be cut down.