Seasonal Care of the Garden
April
Shrubs
Feed ericaceous(acid loving) plants such as rhododendrons,
azaleas, pieris, leucothoe, with a a suitable fertilizer such as Hollytone.
Plant new shrubs and trees. Some, such as beech, birch, maple,
magnolia, dogwood, and holly are best planted in the Spring.
Perennials
Time to plant new perennials. Remember, when the ground is open -
you are planting new plants or digging and dividing existing plants -
is the ideal time to add organic matter in the form of compost, leaf mold,
or aged manure. Organic matter gets used up and needs to be replenished.
Divide and transplant perennials such as hosta, hemerocallis, and Siberian iris
early in month. Perhaps your established Siberian iris looks like a fairy ring, with
a circle of green growth around a bare center. Prepare the new site, remembering
to add organic matter. Take sections of the outer portion with active growth, and
replant. Compost the worn-out center. If you have more division that you need,
share with friends. It is not necessary to keep it all unless you have the space.
If necessary, fertilize perennials as growth begins. You'll do more harm
by over-fertilizing than you might with underfeeding your plants. Lush growth
is attractive to deer, rabbits, insect pests, and diseases. Less is better.
Put peony supports in place before growth gets tall. The circular peony hoops
with an internal grid are the best. At the New York Botanical Garden peony hoops
are laid out as the new shoots just begin to appear. Then, as the shoots elongate,
the hoops are carefully raised and their three legs are attached. Other perennials
such as phlox, tall thalictrums, delphinums, and aconitums that may also need
support should also receive it before they fall over. It is difficult to straighten up.
Annuals
Plant primroses, pansies, and English daisies.
Plant snapdragons late in month if suitably hardened off.
Indoors sow seed of marigolds and zinnias.
Bulbs
Transplant snowdrops, winter aconites etc. when through flowering but still green.
Dig a congested clump. Cover roots with damp newspaper. Dig over the site,
adding organic matter. Divide and replant the bulbs, water, and mulch.
Fertilize newly divided bulbs with half-strength liquid fertilizer. I prefer Jack's Classic
Blossom Booster, analysis 10-30-20. Since spring bulbs quickly go dormant,
a liquid fertilizer that can be promptly absorbed through leaves as well as roots
is especially useful. Repeat with a half-strength feed again in two weeks.
Vegetables
Sow outdoors - seed of beets, carrots, turnips, Swiss chard.
Sow indoors - seed of tomatoes, peppers, and okra.
Set out hardened transplants of cabbage, broccoli, Swiss chard.
Plant strawberries.
Lawns
Mow lawns when grass is 2" tall.
Use pre-emergent crabgrass preventative when forsythia is in bloom.
Miscellaneous
Begin using slug bait.