Garden phlox is susceptible to
mildew, especially when the plants
are growing in dense clumps.

Thinning and deadheading are two measures that add to the good looks of your garden. Thinning refers to selectively eliminating plants or stems. The end result is a more attractive and healthier garden.

 

To reduce the threat of mildew,
improve air circulation by
thinning out dense strands of
phlox. Cut some stems to the
ground.

If your garden contains mildew-prone perennials, such as phlox and beebalm (Monarda didyma), you must ensure adequate air circulation to deter the formation of the fungus. This is simply a matter of periodically cutting enough stems to the ground so that the remaining ones are not crowded. Such surgery in no way harms the plant. Thinning must be done regularly, however, because once mildew sets in it is hard to control without resorting to chemicals.

 

When deadheading mums
and other perennials,
cut back the stem to the
next set of leaves below
the flower head.

One easy way to thin plants is to inspect new shoots in the spring. If -- as is often the case with phlox -- they appear crowded together, simply cut out the woody center of each clump.

 

Do not simply pick off the old
flower heads, or the plants will
be left with unattractive bare
stems.

Deadheading is a grim-sounding term that describes cutting off the unattractive dead heads of flowers in your beds and borders. While deadheading is not essential, it certainly provides great rewards by prolonging the bloom period of most plants, preventing self-seeders from seeding, and ensuring a freshness and neatness in the garden.

Most plants are genetically programmed to produce seeds. Once seed is produced, the plant's function is completed and it can appropriately wither or simply settle in as a foliage plant. If you cut the flower before the seed sets, however, the plant must produce another flower in order to fulfill its goal. The glory of modern breeding is the creation of sterile cultivars; these literally do not know how to stop producing flowers. If you wish to reduce deadheading in your perennial garden, choose sterile cultivars.