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Perennials are plants that live year after year. Trees and shrubs are
perennial. Most garden flowers are herbaceous perennials. This means the
tops of the plants (the leaves, stems, and flowers) die back to the ground
each fall with the first frost or freeze. The roots persist through the
winter, and every spring new plant tops arise. Any plant that lives through
the winter is said to be hardy. Follow our maintenance tips below to ensure
that you will enjoy the blooms year after year.
Watering. Since herbaceous perennials grow back from
the roots every year, it is important to encourage healthy, deep roots.
Proper watering promotes good root development. Make sure that all the
roots are reached when watering. Do not rely on summer rainfall to keep
flower beds watered; plan from the beginning to irrigate them. When watering,
moisten the entire bed thoroughly but do not water so heavily that the
soil becomes soggy. After watering, allow the soil to dry moderately before
watering again. A soaker hose is excellent for watering beds. Water from
the soaker hose seeps directly into the soil without waste and without
splashing leaves and flowers. The slow-moving water does not disturb the
soil or reduce its capacity to absorb water. Water wands and drip systems
are also good. Sprinklers are not as effective as soaker hoses. Water
from sprinklers wets the flowers and foliage, making them susceptible
to diseases. Soil structure may be destroyed by the impact of water drops
falling on its surface; the soil may puddle or crust, preventing free
entry of water and air. The least effective method for watering is with
a hand-held nozzle. Watering with a nozzle has all the objections of watering
with a sprinkler. In addition, gardeners seldom are patient enough to
do a thorough job of watering with a nozzle; not enough water is applied,
and the water that is applied is usually poorly distributed over the bed.
Mulching. Mulches are very useful for maintaining uniform
moisture conditions and reducing weeds in the garden. Soil temperatures
are modified by mulches to various degrees. Organic mulches may add some
nutrients and humus to the soil, improving its tilth and moisture-holding
capacity. Bark, pine needles, and shredded leaves are common organic mulches
used in perennial beds. Most organic mulches should be applied after plants
are well-established and when there is reasonably good soil moisture.
A rule of thumb for perennial borders is to apply mulch in early spring
to get good weed control. Inorganic mulches, such as plastic films and
paper, are applied prior to planting. Black plastic and similar materials
should be spread on land that has been completely prepared for planting
and has a high moisture level. All mulches require care to keep them attractive.
Weeding. Mulching is the best weed control for most
perennials, along with hand-weeding when needed.
Fertilizing. Regular fertilization is necessary. Perennial
plantings can rob the soil of its natural fertility. However, do not fertilize
perennials heavily. A light fertilization program gives a continuous supply
of nutrients to produce healthy plants. Repeat twice at 6 week intervals.
This should be enough to carry plants through the summer. Apply another
treatment of fertilizer to late-blooming plants in late summer. Always
water the bed after applying fertilizer. This will wash the fertilizer
off the foliage and prevent burn. It will also make fertilizer available
to the plants immediately.
Deadheading. After perennials have bloomed, spent flowers
should be removed. Cut flower stems down to a healthy leaf, or to the
ground if there are no more buds. This will keep the beds looking neat
and will prevent plants from wasting energy setting seed. Numerous perennials,
such as delphiniums, can be forced to reblossom if cut back severely after
the first bloom.
Disbudding. To gain large blooms from perennials, as
opposed to more numerous but smaller blooms, plants can be disbudded.
In disbudding, small side buds are removed, allowing the plant to concentrate
its energy to produce one or a few large blooms. Peonies and chrysanthemums
are examples of plants which are often disbudded.
Staking. Most erect perennials are top-heavy, and taller
ones need staking. If plants fall over, the stem will function poorly
where it has been bent. If the stem is cracked, disease organisms can
penetrate the break. Stake plants when you set them out so they will grow
to cover the stakes. When staked, tall perennials can better withstand
hard, driving rain and wind.
Select stakes that will be 6 to 12 inches shorter than the height of
the grown plant. Place stakes behind the plants and sink them into the
ground far enough to be firm. Loosely tie plants to the stakes, using
paper covered wire, plastic, or other soft material. Tie the plant by
making a double loop of the wire with one loop around the plant and the
other around the stake. Never loop the tie around both stake and plant.
The plant will hang to one side and the wire may girdle the stem. Add
ties as the stem lengthens.
Fall Care. In the fall, after the foliage of perennials
has died down, remove dead leaves, stems, and spent flowers. These materials
often harbor insects and disease-causing organisms. Apply winter mulch
after the soil temperature has dropped.
Controlling Insects and Diseases. Although perennials
in general are healthy plants, there are occasionally some problems. It
is advisable to select resistant varieties. Plant perennials in conditions
of light, wind, spacing, and soil textures which are suited to them. Remove
spent flowers, dead leaves, and other plant litter, as these serve as
a source of re-infestation. It is advisable to know the major insect and
disease pests (if any) of each specific plant type grown, so that problems
can be correctly diagnosed and treated if they arise. |