Marion Barnes, Clemson Extension Colleton, and Hampton Counties
As the name suggests, annual clovers require planting each year or re-established depending on their reseeding ability. Natural reseeding is not without risk and is dependent on numerous environmental conditions. A clover variety’s reseeding potential depends on good stands, hard seed percentage and quality, browsing pressure in food plots, climatic conditions (temperature and moisture) during flowering, and seed formation. Many clovers produce a “hard seed” portion that does not germinate immediately after planting. Clovers with good reseeding potential have more “hard” seeds. Hard seeds have tough, impermeable (waxy) seed coats that do not allow water or air to contact the embryo, delaying germination for long periods. Hard seed is a plant mechanism that ensures forage stands are maintained during unfavorable growing conditions, like an “insurance policy.” Hard seeds can remain viable in the soil for several years. Clover species that produce more significant percentages of hard seed provide more dependable voluntary stands. A plant’s hard seed can increase by 40 to 60% during drought conditions. It’s Mother Nature’s way of ensuring plant survival. Below are a list of several annual clover varieties and their reseeding potential:
Clover Reseeding ability (% Hard Seed)
Arrowleaf High (70-90%)
Ball High ( 60-80%)
Rose High (75- 90%)
Balansa Medium to high (20-40%+)
Berseem Low (10% +/-)
Crimson Low to medium (10 – 40%)
Red Low
Subterranean Low
One of the most common clover varieties planted in food plots is Dixie Crimson reseeding clover. Dixie reseeding clover was developed in Georgia in the early 1950s for its reseeding ability and hard seed trait. Although this clover has been around for 60 years, it is still utilized for livestock forage, wildlife food plots, and cover crops. Several varieties of Crimson clover have recently been improved, including AU Sunrise, AU Sunup, and Kentucky Pride.
Proper site selection is the first step in successful clover establishment that impacts natural reseeding. Factors such as soil texture, drainage, soil fertility, pH, and weed pressure should be considered. Although Crimson clover is self-fertile, pollination by insects like honey bees and native bees increases seed production. The colorful crimson cone-shaped seed head contains between 65 and 125 florets, which wither quickly when pollinated. A good indicator of pollination is bright, open florets at the top and withered florets at the bottom of the seed head. Crimson clover seeds mature in about 30 days after pollination. The entire bloom should be dry and brown when fully developed. Once dry, you can pull the seed heads between your thumb and forefinger, and the seed heads should strip easily.
Continue to rub the seed head between your palms to separate the dried florets from the seed. The hard source will “shell out” quickly. Seed yields for Crimson clover vary from 200 lbs. per acre to 800 lbs. per acre or more for commercially harvested seed. Under moderate grazing pressure with good plant density (in cattle forage production situations), 100 to 200 lbs. of seed per acre would be a reasonable estimate, University plant breeders tell me. Crimson clover does have the ability to produce a good deal of origin. However, the hard seed of Crimson clover does not persist in the soil as long as some other clover varieties, but it can be managed for natural reseeding.
Arrowleaf clover is another popular clover planted in wildlife food plot mixes with a high percentage of hard seed (70-90%). For example, the variety Blackhawk released by Texas A & M University in 2013 produces as much as 95% hard seed. Commercial seeds usually need to be sacrificed to facilitate germination. Blooms are often 2 inches long and 1 & 1/4 inches in diameter and contain over 100 florets when flowering, with seed production occurring 4 to 7 weeks in late spring and summer.
To get natural reseeding with annual clover varieties, weed control during the summer is critical. One of the attributes of planting clover is nitrogen fixation and transfer. As your yearly clover plants mature and dry down, more sunlight will reach the ground, causing weeds to germinate and utilize the soil’s nitrogen. Most grassy weeds can be controlled with an application(s) of a labeled selective grass herbicide. Unfortunately, controlling broadleaf weeds germinating during the summer will be more difficult. I am unaware of any labeled herbicide for controlling broadleaf weeds in this situation that does not have long soil residuals or carry-over issues and will not harm clover seedings. Mowing broadleaf weeds throughout the summer may be the only option available.
In mid to late September through early October, when growing conditions are favorable, mowing remnants of standing clover will help disperse the seed and enhance germination by increasing source-to-soil contact. Rainfall and cooler-than-normal temperatures during the summer can cause clover varieties with soft seed coats to germinate prematurely. Young seedlings will die if high temperatures and low rain occur, resulting in stand loss.
Although Crimson clover has a low percentage of hard seed compared to Arrowleaf clover, I have an 8-acre food plot that has successfully reseeded itself for the past two seasons with Dixie Crimson reseeding clover saving the cost of seed and establishment. As the cost of establishing food plots increases, it may be time to take a closer look at reseeding annual clovers and see if they fit into your wildlife food plot management plan.
Information for this article was taken in part from Self-Reseeding Potential of Forage Annual Clovers in the South by Rocky Lemus, Ph.D. Mississippi State University Extension Forage Specialist.
Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, gender, religion, national origin, disability, political beliefs, sexual orientation, gender identity, marital or family status, and is an equal opportunity employer.
