For Specific Plants
In all types of gardens, plants have different soil needs. Some prefer acidity, others alkalinity. Plants that require a rich diet, called heavy feeders, fare poorly with a lean diet or in poor soil. Those that like a lean diet (light feeders) mope with added fertilizer or in very rich soil. But the better your overall tilth, the more flexible your plants will be about then-requirements, from pH to fertilizer.
Whether they're heavy or average feeders, plants grown for their leaves — ornamental foliage plants and leafy vegetables — need more nitrogen. (Corn does, too.) If you're choosing a balanced fertilizer, feed them with one whose N-P-K analysis is roughly equal (5-4-3, 5-5-5). Or, if you're using compost, add some manure to boost nitrogen. Plants grown for their flowers, pods, or fruits need less nitrogen and more phosphorus. They prefer formulas with lower N and higher P numbers (2-4-2,5-10-5). Root vege-^ tables also thrive with less nitrogen but a little extra potash (o-10-10 or 6-8-8, for example).
If your soil has a good nutrient (and pH) balance a»ched£fc organic matter, you'll probably get good results from with any all-purpose balanced fertiliser.
synthetic formulas are 5-10-5, 5-10-10, and 6-8-ii. Most *«tocedo g^ fertilizers have lower formulas but make up for this t>y s m
Wents. Any blend with close to equal numbers |rtilizer nitrogen can be considered all-purpose. 1 he^^)deraleIy fertile soil, 'abels are for mediocre soils. Once you ve acmevea how well your try reducing recommended rates by one-third. Be gv Plants perform.
I Garden Problem-Solver
I Garden Problem-Solver
■ Container Gardening
I Pasteurizing Garden Soil
I Managing Soils for Annual Flowers
I Managing Soils for Perennial Flowers i Managing Soils for Lawns
I Choosing the Right Grass
I Managing Soils for Woody Ornamentals i Managing Soils for Tree Fruits and Nuts
I Herbs Like It Lean
I Growing Perennial Vegetables and Fruits
I AAanaging Soils for Vegetables
I Rotating Vegetable Crops arden Problem-Solver
Don't just assume your plants need fertilizer if they're not doing well. This chart describes common garden problems that may be caused by soil conditions. There isn't room here for all possible problems, or all possible treatments, but this chart will point you in the right direction.
It's hard to generalize plant needs throughout the country. Use the pH levels and other information here only as a guide. Your local Cooperative Extension Service and state agricultural university can provide you with information tailored to your soil and climate.
Symptom
Young plants die
Stunted, pale to yellow plants
Possible Causes
Fertilizer burn Disease/damping off
Low fertility
Acidic soil Poor drainage Compacted soil Insects or diseases Nematodes
Treatment/ Prevention
Stunted, purplish plants Temperature too low
Spots or darkened areas on leaves and/or stems
Low phosphorus Disease
Nutrient deficiency Fertilizer burn
Chemical burn
Treatment/ Prevention
Switch to slow-release fertilizer or use less and keep away from base of plants.
Pasteurize soil (see page 171) for seedlings; use clean pots; improve drainage and avoid overwatering; add compost to soil.
Use foliar fertilizer now; test soil for nutrient balance for later crops.
Test pH and amend as needed.
Add organic matter and see chapter 7.
Break up compaction; see chapter 7.
Inspect plants to identify; use appropriate control.
Consult Cooperative Extension Service for help identifying; solarize soil (see page 160).
Plant at recommended time or use floating row covers (available at garden centers).
Use foliar fertilizer; add bonemeal or other phosphorus source.
Identify and use appropriate control; choose resistant varieties in future.
See symptom chart in appendix.
Avoid getting fertilizer on leaves; dilute foliar types, following label directions.
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Switch to organic controls; follow label directions; don't spray m hot sun.
TO OIEAT SOIL
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Brown leaf tips
Wilting plants
Weak and spindly plants
No fruits form
Dry brown to black rot on blossom end of tomato
Abnormal growth and distorted leaves
Possible Causes
Salt burn
Treatment/ Prevention
Test soil salt levels (see chapter 7); flush salts from container plants.
Low potassium, calcium Test soil.
Dry soil Poor drainage Nematodes
Wilt diseases
Too much nitrogen
Too much water or poor drainage
Too much shade
Plants too close
Too much nitrogen Too hot or too cold Nutrient deficiency
Low calcium Extremely dry soil
Herbicide burn Viral diseases
Irrigate thoroughly. Add organic matter and see chapter 7.
Consult Cooperative Extension Service for help identifying;
solarize soil (see page 160).
Remove infected plants; choose resistant varieties in future (and see chapter 7).
Use less fertilizer next time.
Water less; add organic matter and see chapter 7.
Move plants to sunnier spot. Thin; sow at recommended spacing.
Use less fertilizer next time.
Plant at recommended time and/or use floating row covers. See chart in appendix.
Add calcium source to soil. Irrigate.
Switch to other forms of weed control; follow label directions: don't use herbicide sprayers for other sprays.
Remove infected plants; choose resistant varieties; control insects that spread viruses, or grow plants under floating row covers.
iT * m >m> bv Dick Raymond (Storey Publishing 1991) fevised from Down-to-Earth Gardening Know-How for the 90s, by
Container Gardening
Some people grow plants in containers because they have no garden, others because they have extreme soil, and others just because they enjoy it. Whether indoors or out, plants in containers have slightly different requirements from those growing in the ground.
Providing Water and Drainage
For any container plants, drainage and watering are the main issues. Roots have nowhere to go if the soil is saturated or compacted. Poor drainage not only causes roots to starve for lack of oxygen, it also promotes rot and salt buildup. Even when drainage is adequate, more plants are killed by overwatering than by underwatering.
Container soils compact more easily than garden soils. Watering tends to settle the soil in a pot, and there aren't any earthworms or burrowing insects to loosen it up. Very fine commercial mixes used by some growers may work well for a short period but am easily become compacted in a matter of months.
To ensure long-term health, soils for containers must have a looser texture — more coarse sand and coarse organic matter than garden soils. Perlite, a volcanic material heated to high temperatures to make it expand, is an excellent lightweight substitute for sand that provides even better drainage. Vermiculite (heat-expanded mica) is a good lightweight material for increasing the water-holding ability of container soils.
Keeping Containers Well Fed
Fertilizing is another important issue with container gardening. Overfertilizing causes salt buildup and other problems, but plant roots can't reach beyond the pot to search for nutrients if they're lacking. Since nutrients are easily washed away, more frequent feedings of light doses are better than infrequent full-strength doses.
Traditional liquid fertilizers supply only nitrogen, phosphorus, and potassium, so unless plants are frequently repotted into fresh soil they may suffer from deficiencies of calcium or micronutrients. To provide a fully balanced diet, include some compost in your soil mix and use liquid seaweed, fish emulsion, or compost tea instead of or alternating with synthetic fertilizers.
Soil Polymers: Are They Worth the Cost?
Nontoxic, water-absorbing gels supposedly reduce the need to water plants. These gels are processed into small, beadlike crystals so you can mix a spoonful into the soil mix for each pot. No one argues that these polymers absorb water; a teaspoon can soak up a whole pint! The question is whether this water is then released for plant use.
Tests at the University of California at Riverside show that most of the water remains in the polymers. While there may be a slight increase in humidity (along the lines of setting houseplants on a water-filled tray of gravel), you'll still need to water frequently to keep your plants from drying out.
Polymers work best in pots of very coarse-textured (sandy) soils; in ordinary potting soil you might gain one extra day. But you might also find it harder to tell when plants need water.
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Supplying Adequate Light
With houseplants, light is equally as important as ¡famm (and huniiditN and temperature aren't far behind). Most house plants « M enough. If you checked with a light meter, you'd see that light levels drop off dramatically within a few feet of any window. When plants that SB| aren't getting quite enough light are pushed with lots of fertilizer, they produce weak growth that sends out "come get me" signals to aphid* and other pests. Feed indoor plants just enough to encourage slow, healthy growth. (As a reward, you won't have to repot them as frequently.) In winter, cut back on feeding and watering t0 help plants slow their growth to match winters reduced light levels.
Controlling Salt Buildup
If you see a white crust on the soil of your houseplants, it's salt buildup. Too much salt can cause lenf tips and edges to turn brown. Salts are added by fertilizing and by using hard (alkaline) water. (Your water is hard if it doesn't produce good soapsuds and/or it requires water softeners.) Softened water contains the worst type of salt, sodium chloride. Never use it on your plants — it causes soil as well as growth problems.
Luckily its much easier to flush excess salts out of containers than out of the ground. The method is similar, though: Add enough water to wash away the excess salts. Water your plant(s) until water drains into and nearly fills the saucer below. Empty the saucer and repeat two or three times (more for small saucers). Treat several plants at once so you can let at least 20 minutes pass before repeating.
If a pot shows a heavy salt buildup, repot the plant in fresh soil. Soak the pot and scrub off the salt before replanting. Periodic flushing should keep salts from building up to a visible crust. You can also slow salt buildup by putting some gravel in the tray to lift the pot above any water that drains out.
Watching Your Wattr
If your tap water is hard or very heavily chlorinated, try replacing it with other sources for at least part of the year. Set up a plastic trash can under a downspout during frost-free seasons to collect rainwater. If you use a dehumidi-fier, save the water it produces for your houseplants.
A white crust on the soil of houseplants, or a ring where the soil meets the pot, is caused by excess salts in ferWllzets and in some types of tap water.
A white crust on the soil of houseplants, or a ring where the soil meets the pot, is caused by excess salts in ferWllzets and in some types of tap water.
Homemade Potting Soil
Commercial potting mixes vary in composition, pH, salt levels, nutrient balance, drainage, and how well they hold water. If you haven't had good luck with purchased mixes, try making your own.
Don't: use soil straight from the garden. Even the best garden loams compact too quickly in containers. You must add coarse sand and lots of organic matter to counteract compaction and provide a good balance between drainage and water retention. Adding some soil is good — it supplies a wide array of nutrients. Just be sure to pasteurize soil (see opposite) before using it in mixes in order to kill any harmful organisms. |0
Recipes for Potting Soils
All the ingredients listed below are readily available at your local garden center. Don't use beach sand or road sand, as both could contain enough salt to harm plants. If you use compost, make sure it's finished (try the test on page 61). Clean all mixing tools, bowls, measures, and pots in hot, soapy water or a dishwasher before using. Mix all ingredients thoroughly.
Basic Container Soil Mix
1 part pasteurized soil (should be good, loamy soil; can substitute any commercial potting soil that's not a soilless mix)
1 part compost, leaf mold, shredded fir bark, or peat moss (the last two are acidic and low in nutrients, so compensate by adding 1 tablespoon, or 5 ml, bonemeal per quart — .95 ml — of finished mix)
1 part coarse sand or perlite (for cacti and other plants that require fast drainage, use 1 part sand and 1 part perlite)
Fortified Brooklyn Botanic Garden Mix
4 parts soil 2 parts sand
2 parts leaf mold or compost
1 part dried cow manure to cup (138 ml) bonemeal for every 2Vz gallons (9.5 1) of mix
Cornell University Soilless Mix
8 quarts (7.6 1) fine horticultural vermiculite 8 quarts (7.61) shredded peat moss
2 tablespoons (30 ml) superphosphate (0-20-0)
2 tablespoons (30 ml) ground dolomitic limestone 8 tablespoons (118 ml) dried cow manure or steamed bonemeal
Seed-Germinating Mix
1 part fine commercial soilless mix 1 part perlite 1 part vermiculite
(Contains no nutrients, so feed seedlings periodically with diluted liquid fertilizer starting three weeks after they sprout.)
pasteurizing Garden Soil
If you want to use garden soil in container mixes, pasteurize it first. You can do this in your oven. Pasteurizing kills the organisms that cause damping-off and other soilborne diseases. It's not the same as sterilizing, which kills all soil life. Don't pasteurize fresh compost, however, or you'll kill its disease-controlling organisms.
Cooked soil doesn't smell very good, so use an oven roasting bag to contain odors (and to keep soil from touching the pan). Dampen the soil thoroughly, so it will steam. Close the bag and poke a hole large enough to fit the stern of a meat thermometer. Don't let it get above 180°F
- Heat the soil to 160-170*F (71 to 77°C) for 30 minutes. Periodically insert Osmometer into soil (ovcia touching pon| to check temperature; try setting the^oven to 200°F (93°C) until the soil reaches 165°F (74X1 and then lower the setting a bit. Turn if up again if the soil temperature drops below 155°F |68CC). Moke up tor ony time the so<l measured below the des.red range by adding that period to the timer.
- Heat the soil to 160-170*F (71 to 77°C) for 30 minutes. Periodically insert Osmometer into soil (ovcia touching pon| to check temperature; try setting the^oven to 200°F (93°C) until the soil reaches 165°F (74X1 and then lower the setting a bit. Turn if up again if the soil temperature drops below 155°F |68CC). Moke up tor ony time the so<l measured below the des.red range by adding that period to the timer.
Materials
- Good garden soil
- Shallow roasting pan
- Oven roasting bag
- Meat thermometer
- Pot holders or oven mitts [►Timer
- W&0& boked soil »s ready to use n a mix as soor 35 .ts cool enough to handle. Let it cod completely before piocing seeds or plants in it.
Managing Soils for Annual Flowers
Most annual flowers prefer the same general conditions that vegetables do, except they need less fertilizer./^ general strategies for soil care are the same (unless you're growing annuals mixed in among perennials, in A case use the strategies for perennials). Like vegetable beds, annual beds can be emptied at the end of the se^ (or between successive plantings in mild climates). That makes it convenient to till in chopped leaves, spread compost, or grow a winter cover crop to supply organic matter. J^^M^
Adding Nutrients
Most annuals are average feeders. Modern varieties are bred to withstand neglect, but they'll perform best in well-drained soil that's amended with some organic matter. Many will bloom well with only compost as fert ilizer, assuming your soil's overall nutrient balance is good. A few annuals are heavy feeders; these need soil enriched with ample compost or aged manure plus a midseason sidedressing to keep blooming well. A few others are light feeders; these bloom best in average to somewhat poor soil with no added fertilizer, just a little compost. (See the chart opposite to learn which flowers like light or heavy diets.)
A good rule of thumb is to use half as much fertilizer for annuals as you would for vegetables. If you use liquid fertilizers, mix them at half strength. When choosing a general-purpose blend, opt for one with less nitrogen, such as 5-10-10. If you give flowering annuals too much nitrogen, you'll end up with lots of lush leaves and few blooms.
For average feeders, mixing a slow-release synthetic formula or an organic fertilizer into the bed before planting should supply enough nutrients for the season. If you didn't add nutrients before planting, fertilize about a month after planting or when blooms appear. If plants appear to be slowing down (and it's not because you forgot to clip off faded blooms), try a boost of liquid seaweed diluted to half strength or compost tea (but not manure tea). Sidedress heavy feeders again about midway through the season.
Master Gardening Tip
Master Gardening Tip
Weed Control for Annuals
While many gardeners don't think of cover crops in annual beds, winter rye or annual ryegrass can be a great ally in controlling weeds the following season. Both work best after annuals are killed by frost; growing them under floating row covers allows you to sow them a bit later than normal. Just make sure to dig either under three or four weeks before planting seeds or transplants.
In mild areas with kmg growing seasons, you may need to fertilize again after a couple of months to prolong the display. In very sanely soils, remember to divide' the recommended amount of fertilizer into smaller portions and apply it more frequently throughout the season.
Watering and Mulching
Since annuals don't have time to develop extensive roots capable of reaching far for water, they depend on you to supply water when rains are lacking. Where rains are unreliable, a good organic mulch around your annuals saves you a lot of time while reducing plants1 heat and water stress. Mulch also prevents the soil from crusting, which in turn improves aeration and water penetration.
Caring for Container Plants
Annuals in containers need watering and fertilizing more often than those in the ground. They're usually crowded much more closely together and have a limited supply of soil within reach. Also, nutrients are washed away whenever water runs out the bottom of the container. Don't give container plants a stronger dose, just feed them more often.
feed annuals in containers with a liquid fertilizer such as a^f,f jency emulsion blend a, half strength every two ta three weeks. M^m^ by watching how you, annuals respond. If you use a concentrated lormu
^ch QS 15-30-15, dilute it to one-quarter strength.
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feed annuals in containers with a liquid fertilizer such as a^f,f jency emulsion blend a, half strength every two ta three weeks. M^m^ by watching how you, annuals respond. If you use a concentrated lormu
^ch QS 15-30-15, dilute it to one-quarter strength.
Master Gardening Ti
Annuals Thot R Special Diets
Heavy feeders Megonias, wax or tuberous
{Begonia spp.) Butterfly flower (Srhizanthus x wisefonensts) Caladium (Cakdium x horlu-lanutn)
Canna (Canrn x generally Coleus (Coleus x hybridus) Dahlias (Dahlia hybrids) Heliotrope (Hdiotropucm arborescem) Impatiens (2mpatims hybrids) Larkspur (Cotmlida ambigua) Monkey flower (Munulus x hybridus) Ornamental kale (Brassica olerada) Polka-dot plant (Hypoestes phyllostachya) Snapdragon (Antirrhinum majus)
Sweet pea (Lathyrus odoratus) Torenia (Torenia fournieri)
Light feeders Amaranths (Amaranthus spp.) Calendula (needs even moisture;
- Calendula officinalis) Chinese forget-me-not
- Cynogbsston amabik) Cleome (Cleotne hassleram) Corn cockle (Agrostemnia gilhago) Gazanias {Gazania spp.) Iceland poppy (Papaver nudicaule) Morning-glory (Ipomoca tricolor) Nasturtium (Tropaeolum mains) Painted-tongue (Salpiglossis smuata) Shirley poppy -
Managing Soils for
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