Planting a garden is only half the battle, as plants require maintenance from the day they're in the ground. But maintenance is the heart of gardening. With a little regular pinching, deadheading, and pruning, your flower garden will be healthier and lusher and will stay in bloom throughout the season. Another bonus of regular maintenance is that the more time you spend up-close to your plants, the more likely you are to notice problems while there's still time to correct them.
Most flowers benefit from having their spent flowers removed. This is called deadheading. Flowers that repeat-bloom will often do so only if the old, dying flowers are removed. If the dead flowers remain on the plant, they will go to seed, and the plant will stop producing flowers.
Even plants that bloom only once per season often benefit from deadheading. Once deadheaded, the plant puts its energy into strengthening itself instead of producing seed. Some exceptions to this rule are plants like Astilbe or ornamental grasses that bloom only once but continue to look attractive with their drying seedheads.
Some plants, such as Centaurea montana, benefit from having just their spent buds removed. Centaurea montana will set more buds along the stem, so the entire flowering stem is not removed until all the buds have bloomed and faded.
There are several different techniques for deadheading and maintaining flowering plants. A good pair of garden pruners will make a nice, clean cut, but in some cases, your fingers can do a better job. Depending on your plantings, you may need to remove blooms or stems once or several times during a growing season.
When each flower is on its own stem, such as with Scabiosa plants, it is best to deadhead the entire flowering stem, rather than leaving a gangly, headless stem attached to the plant. Cut off the stem at the base of the plant.
Some plants have very crisp, thin stems and can be deadheaded using your fingers. This type of deadheading is called pinching. Some plants that can be pinched include daylilies, salvia, and coleus. Coleus plants are grown for their foliage, not their flowers. Pinching off the flowers encourages the plants to become bushier and fuller.
Many fall-blooming perennial flowers are pinched early in the season to prevent the plants from becoming tall and floppy and to induce more flower buds. Pinching plants like mums and asters will also move their bloom time back a few weeks, giving you flowers in late September (when the rest of your garden is dying down) rather than in late summer.
To pinch a fall bloomer, start by removing up to one-third of the plant when it reaches about 6 inches tall. Repeat this process every two to three weeks until the 4th of July. Then, let the plant grow and set its flower buds.
Pinching vs. Shearing
Sometimes deadheading with shears makes more sense than pinching. For example, threadleaf coreopsis plants are suitable for deadheading by pinching, but the great quantity of buds and their close proximity to one another on the stem can make pinching coreopsis a nightmare. With plants like this, you are better off waiting until the majority of the buds have bloomed and then shearing the entire plant back by one-half to two-thirds. It won't take long at all for the plant to regroup and set more buds.
Some plants are good candidates for shearing even though they don't have a vast number of flowers. Plants like catmint and perennial geraniums tend to bloom all at once and then decline. By shearing catmint back to a few inches, it encourages the plant to set out new growth and new buds.
Foliage Dieback and Basal Growth
Some early bloomers simply start to look tired by the middle of summer. Their older leaves, toward the outside of the plant, begin drooping and looking worn. A good example is a hardy geranium, which may exhibit as a full clump in spring but becomes an unattractive sprawler by mid-summer.
If you look closely at the early bloomers that have started to droop, you will probably see new growth at the base of the plant. This is called basal growth and it's a signal that the plant is ready to rejuvenate itself. This happens with hardy geranium as well as fern leaf dicentra and mallow.
Pruning to Rejuvenate
When a plant's older leaves start to look worn, you should prune the foliage back either to where there is still fresh growth or all the way back to new basal growth, if there is any. Many new gardeners can't bear the idea of cutting back an entire plant, but this is tough love, and your plants will thank you.
Cutting Back to Shape Plants
Finally, there is a type of cutting back that has nothing to do with removing old flowers or leaves. Some plants, especially fall bloomers, will grow tall and gangly and not be able to support themselves.
For example, New England asters often grow tall without filling out. Once these plants set flowers they will fall over. To encourage the plants to become stockier, cut the plant back by one-third once it has reached about 6 to 8 inches in height. This will encourage it to send out more stems. Let the plant grow about a month, then cut it back by one-third again. It should grow into a full, stocky plant with multiple stems and blooms. The flowers may bloom a bit later than if you hadn't cut, but there will be more of them.