Control of Chinch Bugs Without Pesticides
(www.versicolor.ca/lawns)



Introduction

This page offers some suggestions for establishing and maintaining white clover in lawns. They are based on formal experiments and observations that I and students working with me have conducted on clover in Nova Scotian pastures, [L25,V43] and Halifax turfs [L6, L7, L25] , as well as on 'my "backyard experience". I have also collaborated with a local landscaping company in their development of an "organic approach", which for about 15 years now has included use of white clover.

clonal patch
As noted elsewhere, the traditional turf industry and the various institutes and academic units conducting scientific studies related to turf regard white clover as a weed and are more concerned with getting rid of clover than with establishing it. While attitudes are changing, there is still a general sparcity of scientific information related to establishing and maintaining clover in lawns. On the other hand, there is a voluminous literature on the biology and ecology of white clover in pastures; the earlier literature is well summarized in a 1983 paper by R. Turkington and J.J. Burdon. [V54]

Of course you can't use herbicides if you want clover in the lawn and some other practices of conventional lawncare, e.g., heavy use of nitrogen fertilizer, are also incompatible with maintaining clover. So there is more - at least conceptually - to establishing and maintaining clover in a lawn than just seeding it. Fortunately, in practice it involves doing less, even far less than than is involved in conventional lawncare. That may seem counter-intuitive, but think about this: some of greenest, neatest lawns one can see are those around farm houses where the only management is mowing; farmers don't waste their valuable chemicals if they can help it and most scoff at the idea of applying them to lawns!

                  - David Patriquin

Natural invasion versus seeding

White clover (Trifolium repens) can be established by encouraging spread of naturally invading, wild white clover, or by seeding a new lawn/overseeding an existing lawn with white clover, or a combination of the two approaches.


Photo illustrates the creeping growth habit of white clover. The coin diameter is 1.9 cm. The plant spreads by horizontal stems (stolons) which root at the nodes.

clonal patch
Clonal patch

When white clover invades a lawn naturally, it develops initially in discrete clonal patches of almost pure clover, each one derived from a single plant. Because the patches stand out, they can look unsightly and often the first reaction is to get rid of them. However, if the lawn is managed to encourage clover, it will eventually be distributed throughout the lawn and, with the associated grasses and herbs, contribute to a thick turf and a pleasing mosaic of leaf textures. To accelerate this process, or to establish clover if it is not present, Dutch white clover (sometimes called Shamrock or Irish clover) can be overseeded into a turf or included with the initial seed mix for turf.

Clover species and type

Be sure to use Dutch white clover and not the larger, forage types such as Ladino white, or Alsike or Red Clover. Other small-leaf white clover varieties developed for pastures would also be suitable (and possibly even superior to Dutch white) but are not generally available in Canada.

Spring is the best time to seed To establish clover in existing sod, sow the seed in spring or early fall. Early to mid-April before grass starts growing quickly is the best time because there is little moisture stress and little competition from grass and other broadleaf plants. Clover seed can even be 'frost seeded' in late March or early April on ground that is still mostly frozen; the seed drops into small cracks as the surface alternately thaws during the day and freezes again at night. Early sown seed will germinate when the soil starts to warm up in latter part of April (in HRM).

lawn
Overseeded clover
Late summer/early fall is an alternative time, but is not as good as the spring because the less developed plants (compared to spring-seeded plants) are more likely to be winter-killed. If it's late summer and you're anxious to see some clover on the lawn, seed it then and again in late May or early June of the following year if you don't see good establishment of the fall seeded clover.

If the seed is sown after grass is up and growing quickly, the grass should be cut short and raked first. Seed can be mixed into the soil by raking with a stiff rake and then walking over it (or using a roller). If the seed is sown after mid-May, daily, light watering for seven to ten days (when there is no rain) will ensure good germination and initial establishment. At temperatures above 15oC, most seed will germinate in less than a week, and in as few as 2 to 3 days in summer. For several weeks thereafter, the lawn should be watered as necessary to avoid water stress.

Amount of seed

Jarvis [L33] advises 2 to 8 oz per 1000 sq. ft (equivalent to 61 to 245 grams per 100 sq. meters or 0.61 to 2.45 grams per sq. meter), stating that clover will be dominant at the highest rate. * Leonard [L34] suggests lower rates (0.7 to 1.4 ounces per 1000 sq ft or 21 to 42 grams per 100 sq. meters). Higher rates might be used for less favourable times of year or site conditions, lower amounts for more favourable times and sites, or on more extensive turfs where cost is a factor.
*White clover seed that I have used weighed 5 to 7 milligrams per seed; the lowest seeding rate advised by Jarvis works works out to about 1 seed per 10 x 10 cm area, the highest to 4 seeds per 10 x 10 cm.


Salt-damaged area by walkway healed with clover. See more

For a new lawn, use about 1 part by volume of clover seed for 15 parts of grass seed. It's usually best to sow the clover seed separately from the grass seed; if it's mixed with the grass seed, the smaller, dense clover seed tends to settle out, resulting in a non-uniform, clumpy distribution of clover. Added Note: I have had many inquiries from people who have had disappointing results when they attempt to establish a pure clover lawn, i.e., they sow just clover on newly cultivated soil. You really need both clover AND grass to make a "clover lawn" as they are complementary in their ecological functioning and one supports the other. You may be able to achieve close to 100% clover initially, but it won't be maintained at 100%. If no nitrogen fertilizer is used, the clover cover will stabilize over time at about 40 to 60% of total plant cover, the balance being made up by grasses and non-nitrogen-fixing herbs.

Please note the comments below about persistence, as well: it may be necessary to overseed clover at 2-3 year intervals for a period.

Distributing seed evenly Clover seed can be tricky to distribute evenly and there is a tendency to seed too heavily. I haven't yet seen a drop spreader or broadcast spreader that handles such small seed well. However, there may be some around:

I used a small "Easy Hand-Held" broadcast-type spreader made by Scotts, and at the lowest setting (number 1) the aperature width is only about twice the diameter of a clover seed and about 3/4" long. I was able to walk the entire 200 square meter lawn area in criss-crossing patterns three to four times before I'd used up the 100 grams of seed. (I spread at a conservative 50 grams per 100 square metres)

The shape of the hopper on the Scotts is a bit awkward in my view, but with a bit of cardboard and some tape I was able to fashion it into more of a funnel so the seed falls nicely to the centre.

Setting number 2 on the spreader seems to open the aperature to just over an eighth of an inch which may be a bit rich, but I think some judicious masking could tighten that down a bit for a more controlled spread if needed.

- Frank Tosczak of Victoria BC in an e-mail, 20 Apr., 2008
Small seeds are often coated to make them larger and easier to distribute, but I am not aware of any source of coated seed of Dutch white clover in Canada.

One way to distribute the seed evenly is to mix a prescribed amount of seed for a designated area with some soil, and distribute the soil-seed mix. Jarvis [L33] suggests mixing seed with sawdust or milorganite. Graded sand (grain size approx. 1 mm; most playsand is approx this grade) is another option. The photo at right shows clover seed mixed one part by volume with 30 parts of graded sand for distribution in a broadcast spreader. (Each ruler unit is 1 millimeter; click on image for larger version.)

Mixing seed with soil is a good practice when overseeding clover into bare patches in summer. Pat the soil down and water the lawn daily for about 10 days. (It takes only 2-3 days for the clover to germinate in mid-summer.)

Inoculant

Clover and other legumes are infected by soil bacteria called rhizobia which form nodules on the roots. Nitrogen fixation, the process by which nitrogen gas in the atmosphere is converted into a form that us useable by plants, occurs in the nodules. If nodules, don't form, the clover will not fix nitrogen.

Nodules, 1 to 2 mm in length, are formed on the roots of clover plants infected by soil rhizobia. The nodules are most numerous near the top of the roots. The pink colour indicates they are functional and fixing nitrogen.
The rhizobia that infect clover are quite ubiquitous in temperate soils and usually it is not necessary to introduce them. However, if absolutely no clover is present on a lawn or in the neighborhood, it's advisable to spread legume inoculant with the seed. It can be purchased with the clover seed. To introduce inoculant into an already established lawn, it can be mixed with compost or soil and broadcast with the seed, followed by raking with a stiff rake to open up the soil a bit. Then trample or roll the lawn lightly and water it well if it is dry. Alternatively, take some soil from a lawn or field where clovers are abundant, and mix the clover seed with some of that soil to distribute the clover.

Fertilizers

According to soil analyses, add lime to raise the pH to 6 or 6.5.[V39] Add phosphorous and potassium to bring the levels to a MEDIUM rating. Compost is a good source of phosphorous. Sandy soils may require additions of trace elements.

The most important fertilizer recommendation is to use nitrogen sparingly if at all. Fish fertilizer, feather meal or compost can be used to give the grass an early-season boost before the clover starts growing vigorously; if this is done in spring time, do it early and limit the application to 0.5 lb N per 1000 sq ft (0.25 kg N/100m2). The best time to apply a nitrogen-rich organic fertilizer is late in the fall when the grass stops growing, but is still photosynthesizing. This "dormant feed" fertilization strengthens roots and encourages early greening the next spring. Apply 0.5 lb nitrogen per 1000 sq ft. (0.25 kg N per 100 m2

meadow
Use Red Clover if you establishing a meadow rather than a lawn. Photo of meadow in Magdallen Islands, mowed only 1 time per year, for hay.
Light

Clover does best in full sunlight. It generally will not persist at all in full shade, but can do OK in partial shade. My south-facing front lawn and sidewalk verges are shaded most of the day by deciduous trees. Clover thrives early in the season (before trees are fully leafed out), but by the end of summer is patchy. I overseeded with a shade tolerant grass mix and between those grasses and the clover, the lawn does fine.

Mowing

After sowing seed, the lawn should be mown regularly and fairly close (1.5 to 2 inches or 3.8 to 5 cm) which favors clover over grass by allowing more light to reach the clover. Once the clover is established it can be mown higher again, and should be mowed high (2.5 to 3.5 inches, or 5 to 9 cm) though the droughty months (in Halifax, generally mid-July through August). However even during droughty months, a clover/grass lawn will tolerate much closer mowing than a straight grass lawn. Clippings should be retained on the lawn for maximum retention of nutrients.

Don't use Dutch white clover if you establishing a meadow rather than a lawn. In that case, use a tall-growing hay-type clover such as red clover. (A meadow is a mixture of grasses and herbs that is not mowed or is mowed infrequently, e.g., only 1 or 2 times per year.) The red flowers are also nicer in a meadow situation. Unfortunately, red clovers do not tolerate a lot of mowing, as in lawns.

flowers
Flower heads at different stages: A: in full bloom, B. lower flowers have dropped after fertilization, C: all flowers dropped.

Flowering

In Nova Scotia, white clover starts to flower towards the end of June and goes on flowering fairly vigorously though to mid-August. Newly seeded clover generally flowers only after one full season, i.e., in the 2nd year and beyond. Once-weekly weekly mowing keeps the cover by flowers very low, which is desired by some.

It takes about 4 weeks for clover seed to mature after pollination.[V54] To encourage flowering and local adaptation of the clover and other species through in situ seed production and natural selection, one can stop mowing for 4-6 weeks in mid-summer on part or all of the lawn. If the lawn is not being fertilized with nitrogen and/or excessively watered, growth of the sward will generally be very moderate during this period and the practice provides a holiday from mowing, also an interesting diversity of flowers can develop and these contribute to wildlife conservation, proliferation of natural enemies etc.

Persistence and reseeding

David Slabotsky of the Wolfville Parks Dept. reports that he established white clover on a sports field by mixing a small amount of clover seed into grass mixes used for the yearly overseeding; it took several years for it to take (persist), he says but it is well established now and nitrogen fertilizer is not needed to maintain the field.
mature turf
A mature, self-sustaining clover-grass turf. Regular
mowing is the major input.
Dutch white clover generally does not persist well, and it may require reseeding every two or 3 years until 'it takes'. I have a suspicion that what actually happens is that wild white clovers invade the area and proliferate under the low nitrogen regime (which should be practiced concurrently with seeding clover) and it is the wild white clover that is persisting, not the introduced clover. Even with repeated re-seeding, however, clover is still cheaper than applying nitrogen fertilizer and has lots of other benefits.



Halifax Seed Company (www.halifaxseed.com) sells Dutch white clover seed in bulk. In 2004, I paid $5.50 for 500 grams of seed.

Edmonds Landscaping and Constuction Services Ltd. in Halifax (edmonds.ns.ca) make regular use of Dutch white clover in lawns and have developed some special skills for seeding and maintaining clover in lawns.

A visitor to this site mentioned a new product or class of clovers especially for lawns that has apperaed on the scene in Europe: MicroClover. I wasn't familiar with it and I don't think it is yet available in Canada, but it is available in the U.S. from Hobbs & Hopkins Ltd. in Orgeon. The marketing promotes the qualities cited for clover on this page. Hobbs & Hopkins also market a mix called Fleur de Lawn: "English daises and other small flowers combine with low-growing foliage and a special variety of dwarf perennial rye grass to create a very appealing ground cover." It's good to see such products appearing in the marketplace. Let's hope we can get them in Canada soon! (Also, 'that Canadian companies start producing their own, locally optimized mixes!)

Nicholas wrote (May 28, 2013):
I found some bulk white clover for $3.59/lb at the Scotian Gold Farm Store in Coldbrook, N.S.
Kevin of Cambridge, Ontario, wrote (30 May, 2012):
I ordered a 1kg bag of white clover from the local Home Hardware store for $20. They have it on their website but don't carry it in the stores.

See Home Hardware Clover Seed.
Debra wrote (Sep. 29, 2010):
We carry pure White Dutch Clover Seed and the inoculants in our online store www.seedland.com in the USA.
They also carry a variety of grass, wildflower and wildlife seed.

Tracey wrote (March 17, 2008) about a source of seed in Baltimore, Maryland:
I wanted to mention Meyer seed company in Baltimore as a source of dutch white clover. They sell the seed for $3.50 per pound. If you go in the retail store, it's behind the counter. They also have a mail order catalog. This is where I get much of my organic fertilizer and low grow lawn seeds (creeping red fescue, chewings fescue, and dutch white clover) They don't have a specific grass seed mix for low-grow lawns, but they sell a lot of lawn seed that one would use, like the fescues mentioned above.

Meyer Seed Company
600 South Caroline Street
Baltimore, MD 21231
(410) 342-4224

Free 32-page catalog. General seeds. Mostly vegetables for Maryland and the Mid- Atlantic. Packets to pounds. Also supplies, bird seed. Also, retail location in Baltimore City.
Valerie wrote (June 8, '09)
I bought a 500 g bag of clover at Scott's Garden Centre in Orillia for about $6.99. The address on the bag is Speare Seeds, Harriston, ON, N0G 1Z0 www.speareseeds.ca
Dave wrote (May 26, '08):
SouthView Nursery on SouthView drive in Sudbury, Ontario, sells clover. They have it in bulk you just scoop out what you need and the price is very reasonable.

John Wrote (July 5, '08)

I bought Dutch white clover seed for $7.40/lb at Southern States in Mount Airy, Maryland. It is kept in the horse supply section, not where the lawn and pasture seed is displayed.

Sarah wrote (May 28, 2009)
Sheridan Nurseries in Scarborough [Ontario] has white clover seed: 250 gram bag for $7.99.
Jonathan wrote, June 5, 2013:
For any of your readers in British Columbia, I found inoculated White Dutch Clover at the following vendor: http://www.westcoastseeds.com
Shelly wrote, May 22, 2013:
Baden Feed and Supply [Baden, Ont.] http://www.badenfeed.com/ also sells white clover seed.
Patrick wrote (3 Sep. 2012): I picked up white clover seed at my local Co-op Atlantic Farmers store in Sydney Nova Scotia - about $2.29 a pound.

Mark wrote (May 17, 2012): In Mississauga, Dutch white clover seeds for lawns are available at Sheridan Nurseries on Southdown Rd and Rona on Argentia Rd.

Sheryll wrote (March 27, 2012): Botanix in Alliston, Ontario sells white clover.

Christine wrote (April 29, 2008) about a source in southern Ontario
It took LOTS of searching but I found this source for seeds: http://www.oscseeds.com/

OSC Seeds
P.O. Box 7, Waterloo ON, N2J 3Z6
Telephone: 519-886-0557, Fax: 519-886-0605
Under "Legumes & Forage"

Amazing price. Super, super fast shipping.

Put seed in today, mixed with grass seed on bare yard area about 4' x 30'


From Lorraine (May 28, '08):
We were able to purchase Dutch White Clover through Bradford Greenhouses Garden Gallery in Barrie, Ontario which was from Quality Seeds Ltd. Woodbridge, ON (905) 856-7333. It was $6.99 for 500g (A comparable price to OSC seeds but without the shipping costs)
From Calvin (June 17, '08)
Apache Seeds in Edmonton on 149th St and Stony Plain Road sells white dutch clover as well as a number of prairie blended seed mixes.
From Patricia (June 25, '08)
There is a shop in Brantford, Ontario that sells White Clover. The location is 73 Wadsworth Street. The store sells birdseed and the like and the name is "Grandview". The phone number is 519-752-5349.
From Mark (March 31, '09)
In Ottawa, white clover seed is available at Richie Feed and Seed.
From Tom (May 8, 2010)
My wife found subject seed at Blomidon Nursery in Wolfville [Nova Scotia]. We're starting our move toward a clover lawn this year.
Thanks, All!

Please forward names of any other local distributors of seed and companies that actively market white clover lawns to patriqui@dal.ca


Page posted 26 May 2004
Modified 5 June 2013.