Common Disease Problems
Blue Mold: Bruising or mechanical injury can cause a blue mold to form on the injured part of the bulb. This is harmless to the bulb. Burpee Recommends: Carefully washed off the bulb prior to planting. Dust with a fungicide recommended by your Cooperative Extension Service.
Botrytis: This fungus causes a grey mold in the necks and bulbs. It thrives in cool wet weather conditions. Burpee Recommends: Remove affected plant parts, avoid watering at night and getting water on the plant when watering. Make sure plants have good air circulation. Contact your Cooperative Extension Service for fungicide recommendations.
Downy Mildew: This fungus causes whitish grey patches on the undersides and eventually both sides of the leaves. Burpee Recommends: Rotate crops with plants in a different family. Avoid overhead watering. Provide adequate air circulation, do not overcrowd plants. Do not work around plants when they are wet.
Pink Root Rot: A fungus that attacks roots causing them to turn a light pink, then red and eventually purple-brown and causing them to shrivel. Infected plants show signs of nutrient deficiencies and drought because the roots cannot take up water and nutrients. Plants are stunted. The disease lives in the soil for several years and thrives in warm temperatures. Burpee Recommends: Plant as early as possible so the bulb of the plant growth will be in cooler temperatures. Rotate crops and plant resistant varieties.
Rust: A number of fungus diseases that rust colored spots on foliage and stalks. Burpee Recommends: Plant resistant varieties. Practice crop rotation. Contact your Cooperative Extension Service for recommendations.
Common Pest and Cultural Problems
Bulb Mites: Shiny, creamy white, bulbous-appearing mites. They penetrate the outer layer of the tissue creating openings for rotting organisms. They are most damaging during cool, wet weather when plant growth is slowed down. Burpee Recommends: Crop rotation. Clean cloves before planting.
Bulb Nematodes: Microscopic worm-like pests that live and reproduce inside the garlic bulb, feeding on the stems, leaves and bulbs. It can live for several years in the soil. Burpee Recommends: You can have your soil tested by your local Cooperative Extension Service to see if you have nematodes. Do not plant into infested soil and do not plant related crops into the soil for several years.
Leafminers: These insects bore just under the leaf surface causing irregular serpentine lines. The larvae are yellow cylindrical maggots and the adults are small black and yellow flies. They do not usually kill plants, but disfigure the foliage. Burpee Recommends: Remove affected foliage if damage is particularly severe.
Slugs: These pests leave large holes in the foliage or eat leaves entirely. They leave a slime trail, feed at night and are mostly a problem in damp weather. Burpee Recommends: Hand pick, at night if possible. You can try attracting the slugs to traps either using cornmeal or beer. For a beer trap, dig a hole in the ground and place a large cup or bowl into the hole; use something that has steep sides so that the slugs can’t crawl back out when they’re finished. Fill the bowl about ¾ of the way full with beer, and let it sit overnight. In the morning, the bowl should be full of drowned slugs that can be dumped out for the birds to eat. For a cornmeal trap, put a tablespoon or two of cornmeal in a jar and put it on its side near the plants. Slugs are attracted to the scent but they cannot digest it and it will kill them. You can also try placing a barrier around your plants of diatomaceous earth or even coffee grounds. They cannot crawl over these.
Thrips: Thrips are tiny needle-thin insects that are black or straw colored. They suck the juices of plants and attack leaves and stems. The plant will have a stippling, discolored flecking or silvering of the leaf surface. Thrips can spread many diseases from plant to plant. Burpee Recommends: Many thrips may be repelled by sheets of aluminum foil spread between rows of plants. Remove weeds from the bed and remove debris from the bed after frost. Check with your Cooperative Extension Service for pest controls.
Harvest and Preserving Tips
- Harvest when the foliage begins to yellow. At this time bend back the tops to hasten yellowing and drying of the tops. Feel around the top of the bulb to make sure the cloves have formed.
- Pull up the plants and allow them to dry in the sun for a few hours. Spread them out in a well-ventilated location until the tops are thoroughly dry, about 3-4 weeks.
- Cut off the tops 1-2 inches above the bulbs, or braid the tops together for softneck varieties. Store loose bulbs in a dry, cool, airy place in baskets, or hang braided garlic strings.
- Garlic may be frozen, make into vinegar, or made into garlic salt.
How to Grow
- Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their seeds from germinating. Avoid disturbing the soil around the plants when weeding.
- Keep plants well watered during dry periods to promote rapid, uninterrupted growth. Plants need about 1 inch of rain per week during the growing season. Use a rain gauge to check to see if you need to add water. It’s best to water with a drip or trickle system that delivers water at low pressure at the soil level. If you water with overhead sprinklers, water early in the day so the foliage has time to dry off before evening, to minimize disease problems. Keep the soil moist but not saturated.
- Monitor for pests and diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area.
How to Sow
- In the South, plant cloves in the fall for a spring harvest. In the North, plant softneck varieties in early spring for a summer harvest and hardneck varieties in fall for a spring harvest.
- Plant cloves in well-drained soil rich in organic matter and full sun when you receive your bulbs. Do not hold your bulbs until the next planting season.
- Each bulb is made up of several sections called “cloves” held together by a thin, papery covering. Before planting break the cloves apart and plant each separately.
- Choose a location in full sun with well-drained soil where you did not plant garlic the previous year.
- Work organic matter into your soil at least 6-8 inches deep, removing stones, then level and smooth.
- Plant in rows 1-2 feet apart, 3-4 inches deep and 4 inches apart. Firm lightly and water gently.
- Plant cloves with the pointed side up.
- Spring planted garlic emerges in 14-21 days. Fall planted garlic may not emerge until spring.
- If the garlic emerges in the fall and a heavy frost is expected, mulch tender greens for protection.
How to Grow