PlantinG and renovation 55
total, or 0.1, will be needed for 100 sq. ft. (Remember, too, that because the
numbers for the fertilizer refer to percentage of N, P, and K by weight, a 5–10–5
fertilizer has 5 percent N, or 0.05.)0.1 lb. N per 100 sq. ft. ÷ 0.05 N = 2 lb. fert. per 100 sq. ft.Next, convert pounds to cups for easy measuring. For the general-size pelleted
material that I use, 1 lb. of fertilizer equals 1 1/2 cups. (You should test and weigh
your own material because different fertilizers will have differences in granular
size and bulk density.) So the 2 lb. of fertilizer needed for a 100-sq.-ft. area
translates to 3 cups of fertilizer per 100 sq. ft.
If you’re using the 12–12–12 fertilizer, 0.83 lb. of fertilizer is needed per 1000
sq. ft. (That is, 5/12 of 2 lb. is 0.83 lb.) I round up to 1 lb. per 100 sq. ft. when using
12–12–12.
I also use organic fertilizers, including cottonseed meal (6 percent nitrogen,
2–3 percent phosphorus, 2 percent potassium), colloidal phosphate (0 percent
nitrogen, 18–22 percent phosphorus, 0 percent potassium, 27 percent calcium,
1.7 percent iron, plus silicas and 14 other trace minerals), and greens and (0
percent nitrogen, 1 percent phosphorus, 5–7 percent potassium, 50 percent silica,
18–23 percent iron oxide, and 22 trace minerals) as well as Earth-Right (a com-
posted soil conditioner containing animal, mineral, and sea products that can be
applied as a topdressing) as substitutes for chemical fertilizers.
Perennials such as delphiniums, peonies, chrysanthemums, daisies, phlox,
astilbes, and repeat-blooming daylilies are heavy feeders and may need a spring
application of fertilizer as well as a summer application with a water-soluble
fertilizer, even in soils high in organic matter. Delphiniums, for example,
produce pale green new growth after being cut back, and this is a sign that
fertilizing is needed. Repeat-blooming daylilies, such as Hemerocallis ‘Happy
Returns’, especially benefit from foliar feeding (spraying liquid fertilizer directly
on the surface of the leaves when first in bud). A water-soluble chemical (Peters’
20–20–20 or something similar) or organic fertilizer (such as fish emulsion or a
seaweed-based product) can be chosen for foliar feeding. Foliar feeding results in
a quicker uptake of nutrients. It should be performed early in the morning on an
overcast day to prevent burning.
Again I must stress that proper initial preparation of your beds with organic
matter can save on time and maintenance later. This point is clearly displayed
when it comes to fertilizing perennials. If the soil is rich and the growing
conditions are good, supplemental fertilizer is not necessary for most perennials.
Topdressing with 1 to 2 in. of a high-quality aged compost every 3 years is the best
approach to providing nutrients to most perennials, with regional adjustments
possibly necessary. Heavy feeders like delphiniums may need some supplemen-
tal fertilizing.WEED CONTROL
Ensuring that a bed is free of perennial weeds before planting is the first critical
step toward weed control. If you are going to skip this detail, surrender now!
Close spacing of perennials is of benefit not only to the commercial grower
selling many plants, but also to the home gardener because it helps eliminate weed
competition. The biggest battle with weeds will be fought in the early spring, when
weeds have sufficient light and room to grow since the perennials are still small. In
the spring it can be difficult for even the savvy gardener to distinguish between a
weed and a desirable perennial: “If in doubt, don’t pull it out.” A bit later in the
plant’s growth you will be able to make a clear call. Try to keep up with the weeds,
or a relatively easy, methodical task can turn into a procrastinator’s nightmare.