Learn About Ammi Majus

How to Sow

  • Direct sow seeds in average soil in full sun after all danger of frost. It is not recommended to start indoors as plants are challenging to transplant. Sow where you want them to grow.
  • Prepare the soil by removing weeds and working organic matter into the top 6-8 inches of soil; then level and smooth. Ammi majus prefers a cool, moist soil.
  • Most plants respond well to soils amended with organic matter. Compost is a wonderful form of organic matter with a good balance of nutrients and an ideal pH level, it can be added to your planting area at any time. If compost is not available, top dress the soil after planting with 1-2 inches of organic mulch, which will begin to breakdown into compost. After the growing season, a soil test will indicate what soil amendments are needed for the following season.
  • Sow seeds thinly and cover with ¼ inch of soil.
  • Firm soil lightly, water and keep evenly moist.
  • Seedlings will emerge in 7-21 days.

 

How to Grow

  • Thin to stand about 15-18 inches apart when 1 inch high.
  • 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.
  • Mulches also help retain soil moisture and maintain even soil temperatures. For annuals an organic mulch of shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
  • Keep soil evenly moist but not wet.
  • No fertilizer is needed unless the soil is poor. Do not over fertilize.
  • Monitor for pests and diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area.
  • Remove plants after they are killed by frost in fall to avoid disease issues the following year.

 

Growing tips

  • Ammi majus blooms in late spring to early summer
  • Harvest flowers when 2/3 to ¾ open. They make lovely dried flowers.
  • In windy areas Ammi majus may need to be staked.
  • Wear gloves when working with Ammi majus, as some people develop a skin rash.

 

Common Pests and Problems

Common Disease Problems

Botrytis (Gray Mold): This fungus causes a grey mold on flowers, leaves, stems and buds. 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.

Damping Off: This is one of the most common problems when starting plants from seed. The seedling emerges and appears healthy; then it suddenly wilts and dies for no obvious reason. Damping off is caused by a fungus that is active when there is abundant moisture and soils and air temperatures are above 68 degrees F. Typically, this indicates that the soil is too wet or contains high amounts of nitrogen fertilizer. Burpee Recommends: Keep seedlings moist but do not overwater; avoid over-fertilizing your seedlings; thin out seedlings to avoid overcrowding; make sure the plants are getting good air circulation.

Powdery Mildew: This fungus disease occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends: Avoid powdery mildew by providing good air circulation for the plants by good spacing and pruning. Contact your Cooperative Extension Service for fungicide recommendations.

Common Pest and Cultural Problems

Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.

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 flower petals, 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.

FAQ

Should I deadhead my Ammi majus? Yes keeping the plant dead headed will extend the bloom time.

Can I indoor sow Ammi majus? We recommend direct sowing because the plant is difficult to transplant.

Does Ammi majus make a good cut flower? Yes its delicate look makes it an excellent filler flower, and it can last 3-10 days as a cut flower. Wear gloves when working with Ammi majus as some people can get a rash from its sap.

Can Ammi majus be used as a dried flower? Yes, hang flowers upside down to dry. Make sure it is dried in a dark place or the white flowers may turn brown.

Can I grow Ammi majus in a container? We do not recommend this, the plant grows 4 feet tall.

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