What to Feed and When
Before you buy or use fertilizer, read the instructions on the packet to
make sure it is what you want. Plants can only take up nutrients in a
solution, so always water after feeding.
- Vegetables need a general fertilizer, such as blood, fish, and bone,
applied before planting or sowing.
- Fruiting crops, such as tomatoes, zucchini, pumpkins, and peppers,
appreciate an application of liquid tomato fertilizer about once every
two or three weeks.
- Permanent plants, especially fruit trees or bushes, benefit from a
general fertilizer, such as blood, fish, and bone, in early spring after
weeding and before mulching.
- Roses should be treated with a special rose fertilizer in spring right
- Temporary plantings in containers and hanging baskets soon use up the
limited nutrients in the potting mix, so use a general-purpose liquid
fertilizer every ten days in summer. For permanent plantings in
containers, such as shrubs, push controlled-release fertilizer tablets
or pellets into the potting mix in spring.
- Lawns need a fertilizer with a high nitrogen content in spring for
lush leaf growth, and one that encourages root development in fall.
- Shrubs should be fertilized with a general-purpose fertilizer in spring. Sprinkle it around the plant, rake it in, then water.
Correct Fertilizer Levels
When fertilizing, resist the temptation to add a little extra fertilizer
for good measure; more plants are lost through overfeeding than
underfeeding. Always follow recommended application rates and dilute
liquid fertilizer accurately. If in doubt, err on the side of caution,
since too much fertilizer promotes lush growth that is more vulnerable
to pest and disease attack, and summer bedding tends to flower better if
slightly underfed. Overfeeding can also cause “reverse osmosis,” where
plants lose, rather than absorb, nutrients.
Yellowing between the leaf veins is a common sign of malnutrition. It may indicate a lack of magnesium in acidic soil or crops given potassium-rich tomato fertilizer; the leaves may also be tinted brown or red. Apply Epsom salts (magnesium sulfate) in fall to replenish nutrients. Potassium deficiency also causes yellowing, purple or brown tints, and poor flowering, although a lack of flowers may indicate too much nitrogen. Regular application of organic matter promotes healthy plants. Beware of overfertilizing, though—this may actually reduce the number of flowers produced by some annuals and perennials.