(Trifolium incarnatum ‘Crimson’)
Crimson Clover is an annual flower that is native to Europe, but can be found growing across the U.S. in nearly every state. At maturity, this plant reaches the height of 1-3' and features hairy rosette unbranched stems, 1/2-1” heart shaped leaflets, and 1-2 1/2” cylindrical flower heads that bare ½ vibrant red florets. This plant can be grown in a container, it attracts bees and butterflies, is both drought and frost tolerant, and provides forage to livestock!
Genus: Trifolium
Species: incarnatum
Variety: Crimson Clover
Also known as: Carnation Clover, Italian Clover, French Clover.
Native Range: Albania, Austria, Belgium, Bulgaria, Corse, Czechoslovakia, Denmark, East Aegean Is., Finland, France, Germany, Great Britain, Hungary, Iran, Italy, Kriti, Netherlands, Norway, Poland, Portugal, Romania, Sardegna, Sicilia, South European Russi, Spain, Sweden, Switzerland, Turkey, Turkey-in-Europe, Yugoslavia.
Introduced into: Alabama, Algeria, Baltic States, Belarus, Central European Rus, Chatham Is., Chile Central, China North-Central, China Southeast, Egypt, Illinois, India, Japan, Kentucky, Korea, Krym, Madeira, Morocco, New South Wales, New York, New Zealand North, New Zealand South, North Caucasus, Northern Provinces, Northwest European R, Pakistan, Queensland, Sakhalin, South Australia, Tennessee, Transcaucasus, Ukraine, Vermont, Victoria, Western Australia
Ease of Growing: Easy
Grown as: Annual
Maturity (Bloom): Summer
Hardiness: In the US, crimson clover is hardy to Zone 6. Established plantings made in early fall can tolerate temperatures to 0°F or slightly colder.
Crops: Spring, Summer, Fall
Growing Conditions: Cold. These cover crops generally require cooler temperatures and adequate water.
Outdoor Growing Temp: 40°F - 85°F
Min Outdoor Soil Temp: 30°F. Most cool weather cover crop should be started when temperatures are still in the 60's to allow the plants to establish before winter, which also prevents Winterkill.
Start Indoors: No
Start Outdoors: Yes
Containers: No
Small Gardens: No
Light: Sun: min. 6 hours daily (Cold, Cool). Cover crops need full sun when growing in winter, as days are shorter and the sun is lower in the sky. If grown in summer many will tolerate light shade (though they grow best in full sun).
Water: Most of these crops are not particularly drought tolerant and will need regular watering in dry climates (especially when germinating and getting established). However they are mostly grown during the winter when the soil is fairly moist, so don't usually require much irrigation.
Feeder: Light. You do not need to fertilize cover crop in established gardens, as there will be plenty of nutrients in the garden to meet their needs. Since you will be incorporating them back in to the soil, growing them doesn't remove any nutrients from the soil. The leguminous cover crops also fix nitrogen and eventually add it to the soil.
Attracts beneficial insects?: Yes. Bees and Earthworms love it and is also a protein-rich forage crop for cattle and livestock
Containers: Yes. suitable for 5 gallon containers and up.
Height: 12-18"
Spacing: 12-15"
Sow Depth: Below soil surface.
Produces: hairy rosette unbranched stems, 1/2-1” heart shaped leaflets, and 1-2 1/2” cylindrical flower heads that bare ½ vibrant red florets.
USDA Grow Zone: 3a-10b
Most cover crops are not too fussy about soil, as they have been selected for vigorous growth almost anywhere. If your soil is unusually acidic you may want to add lime.
Soil Preparation:
Before sowing, 1 time: Cover crops don't usually receive much soil preparation - you simply scatter the seed onto the bed at the required density and mix it into the top 2" of soil with a rake.
Lime (Calcium), before sowing, 1 time: Optional: This depends on the pH of your soil. If your soil is too acidic, amend it with some ground lime.
Starting your Crimson Clover Seeds Outdoors in Fall
Crimson Clover seeds are usually broadcast on to the bed and incorporated into the top 2" of soil with a rake 6-8 weeks before the first frost date of your area. You can also simply scatter the seed on the soil and cover with an inch of garden soil. Seed shouldn't be left exposed on the soil surface as it will be very prone to drying out, or getting eaten by birds (you may have to net or use row covers to prevent this). It is essential to keep the soil moist until all of the seedlings have germinated and are growing well.
You don't have to have a completely clear bed to plant. If you have productive crops growing there, you can simply sow the seed around them.
If you haven't grown a leguminous cover cop within the last three years you may want to inoculate the seed to improve the rate of nitrogen fixation. This requires the proper strain of bacteria for the crop and is applied to the seed prior to planting. Requires Pea Vetch or Garden Combination Inoculant.
Support: No
If you find that birds are eating the seeds you've planted, trying covering the beds with row covers.
Generally you will incorporate the plants into the soil before they flower.
Water Needs: Low. Most of these crops are not particularly drought tolerant and will need regular watering in dry climates (especially when germinating and getting established). However they are mostly grown during the winter when the soil is fairly moist, so don't usually require much irrigation.
Fertilizer Needs: Light. You do not need to fertilize cover crop in established gardens, as there will be plenty of nutrients in the garden to meet their needs. Since you will be incorporating them back in to the soil, growing them doesn't remove any nutrients from the soil.
The leguminous cover crops also fix nitrogen and eventually add it to the soil.
Watering, regularly: Water, 0.5 inches regularly, 2 times a week. Most cover crops need moist soil for best growth. This is normally supplied by mother nature, but if it isn't you will have to irrigate.
Protecting, after sowing: Netting, after sowing, 1 time. In many areas birds will look upon your newly sown cover crop as a fall treat. They will actively search for the seed in the soil and eat the newly emerging shoots. In this case you may have to net the beds or use row covers.
Watering, after sowing: Water, 1 inches, after sowing, 5 times a week. It is essential that the germinating seeds receive adequate water, so if it doesn't rain you will have to irrigate regularly.
Support: No
The optimal time to till in your cover crop is when 50% of the flowers are in bloom. At this time there is the maximum amount of biomass and a good proportion of carbon. The biomass will be rapidly decomposed by soil microbes, who will then return nitrogen and other elements to the soil for the next crop. The length of time required to reach this stage will vary hugely, depending on the climate and the crop.
Companion Planting
Problems
Suggested Varieties
(Centaurea cyanus ‘Dwarf Blue’)
Dwarf Blue Cornflower is an annual flower that is native to Europe that can be found growing in open fields and along railroads from coast to coast of the United States. At maturity, this plant reaches the height of 1-3' and features grayish green, blade-like foliage and long stems topped by a 1” circlet of tiny lavender blue flowers with a darker center. This plant attracts bees and butterflies, provides bird forage, tolerates drought and frost, makes dye, self sows, and is great as a cut flower!
(Centaurea cyanus ‘Tall Blue’)
Tall Blue Cornflower is an annual flower that is native to Europe that can be found growing in open fields and along railroads from coast to coast of the United States. At maturity, this plant reaches the height of 1-3' and features grayish green, blade-like foliage and long stems topped by a 1” circlet of tiny lavender blue flowers with a darker center. This plant attracts bees and butterflies, provides bird forage, tolerates drought and frost, makes dye, self sows, and is great as a cut flower!
(Centaurea cyanus ‘Tall Pink’)
Tall Pink Cornflower is an annual flower that is native to Europe that can be found growing in open fields and along railroads from coast to coast of the United States. At maturity, this plant reaches the height of 1-3' and features grayish green, blade-like foliage and long stems topped by a 1-1½” circlet of tiny pale pink flowers with a darker pink center. This plant attracts bees and butterflies, provides bird forage, tolerates drought and frost, makes dye, self sows, and is great as a cut flower!
(Brassica oleracea 'Calabrese Green Sprouting')
Calabrese Green Sprouting Broccoli is an Italian heirloom, hardy, cool weather annual vegetable that is native to the Mediterranean region, but brought to America by the D'Arrigo brothers between 1904-11, and first offered to the public in 1923. At maturity, this plant reaches the height of 30-36” and features erect stalks, 6” bluish-green centered floret, multiple side shoots, and yellow flowers. This plant can be grown in a container, is rabbit safe, tolerates light frost, and is edible.
(Brassica oleracea 'Purple Sprouting')
Purple Sprouting Broccoli is an Italian heirloom, hardy, cool weather annual vegetable that is native to the Mediterranean region, but was introduced to the United States not long after they were listed in the French Vilmorin-Andrieux seed catalog in 1885. At maturity, this plant reaches the height of 18-36” and features thin stem, side shoots of loose clusters of 3-5” purple florets, and bladed leaves. This plant can be grown in a container, is rabbit safe, tolerates frost, and is edible.
(Brassica oleracea 'Waltham 29')
Waltham 29 Broccoli is a heirloom, hardy, cool weather annual vegetable that is native to Waltham, MA., where it was developed by the University of Massachusetts in 1950. At maturity, this plant reaches the height of 18-24” and features a 4-6” blue-green central broccoli head, and side shoots that bare 1” florets. This plant can be grown in a container, is rabbit safe, tolerates frost, and is edible.