Clover as a lawn component - Ask Extension
I'm concerned about chemicals in our environment and have considered using clover to fill some bare spots in my lawn. What is the best variety for Wi...
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Clover as a lawn component #819854
Asked February 06, 2023, 6:48 PM EST
I'm concerned about chemicals in our environment and have considered using clover to fill some bare spots in my lawn. What is the best variety for Willamette Valley that would work with an existing lawn? Am I correct that if I over seed with clover, I can reduce or eliminate fertilizer since clover fixes nitrogen from the air? Will there be any issues with summer irrigation or special considerations about the height of the mower? Thank you
Marion County Oregon
Expert Response
Hello Mark,
Clover generally blends well with lawn grasses assuming you do not mind bees flying around. Yes, clover fixes nitrogen and can reduce or eliminate your need for nitrogen depending on the species of grass you have. In general, clover releases nitrogen in the fall which may carry over a little to the spring. In summer, the clover is forming nodules and doesn't release much nitrogen, if any. But summer is the time of year that organic nitrogen gets released from organic matter. Over time, soils accumulate organic matter so you need to fertilize lawns less and less.
Keep in mind that grasses with a higher fertilility requirement will still need to be fertilized some (e.g. perennial ryegrass and tall fescue) to look their best. Be sure to mulch your clippings (i.e. return them to the lawn) when you mow, as they are a big source of nitrogen as well.
On the downside, clover tends not to persist and you will need to re-seed periodically. Also, clover is not very traffic tolerant so it will not persist where there is consistent walking or playing. Clover also needs to be irrigated some in the summer, but it doesn't need more water than your lawn. You could add yarrow into the mix which is more drought tolerant and you can use the yarrow (Achillea millefolium) as an indicator of when to water (i.e. when the yarrow starts to wilt, it is time to water). Both yarrow and clover are part of the ecolawn mix developed by Professor Tom Cook at Oregon State University.
We have used 'Micro-clover' (DLF International Seed) and strawberry clover in our trials. 'Micro-clover' is touted to be smaller, but in my experience, the size of clover depends mostly on how high and frequently you mow it. Clover can grow quite high - probably a foot or more and when it is allowed to grow, the leaves get bigger. 'Micro-clover' has white flowers and strawberry clover has pinkish red flowers. I don't think there is much difference between 'Micro-clover' and "normal" white clover (trifolium repens). They will both work.
Whether or not you use fertilizers is completely up to you. It is about making choices about how you want your lawn to look. There are some grasses that can survive better without much or any fertilizer applications (e.g. fine fescues and bentgrass). Many lawns in western Oregon naturally convert to bentgrass because it is already in the soil seed bank, it can survive long term drought like we get in western Oregon, and it can survive without any fertilizer. These are the standard maintenance practices for many people (i.e. do nothing other than mow it occassionally).
Having said that, if you don't water your lawn at all, and don't fertilize it, your lawn will lose density and weeds will encroach and you will end up with a lawn full of weeds (which is fine if you don't care about having a lawn full of weeds). However, with a little maintenance (1, maybe 2, fertilizer applications a year) and some irrigation in the summer, your lawn can maintain it's health enough to keep its density and drastically reduce weed encroachment. So, in essence, if you don't want weeds in your lawn, your choice is to make 1 or 2 fertilizer applications per year or apply herbicides fairly often.
If you don't have an issue with bees, and you don't mind the look of clover, I think it makes sense to interseed some clover in your lawn to simply reduce the number of fertilizer applications. Tom Cook, incidentally, has a colonial bentgrass lawn with clover and he rarely fertilizes his lawn. The only caveot to this is if your soil has been hauled in and it does not have an accumulation of organic matter that can release nitrogen when the temperatures warm up, you will need to fertilize for a few years until the organic nitrogen builds up in your soil.
I hope this helps. Good luck.
Clover generally blends well with lawn grasses assuming you do not mind bees flying around. Yes, clover fixes nitrogen and can reduce or eliminate your need for nitrogen depending on the species of grass you have. In general, clover releases nitrogen in the fall which may carry over a little to the spring. In summer, the clover is forming nodules and doesn't release much nitrogen, if any. But summer is the time of year that organic nitrogen gets released from organic matter. Over time, soils accumulate organic matter so you need to fertilize lawns less and less.
Keep in mind that grasses with a higher fertilility requirement will still need to be fertilized some (e.g. perennial ryegrass and tall fescue) to look their best. Be sure to mulch your clippings (i.e. return them to the lawn) when you mow, as they are a big source of nitrogen as well.
On the downside, clover tends not to persist and you will need to re-seed periodically. Also, clover is not very traffic tolerant so it will not persist where there is consistent walking or playing. Clover also needs to be irrigated some in the summer, but it doesn't need more water than your lawn. You could add yarrow into the mix which is more drought tolerant and you can use the yarrow (Achillea millefolium) as an indicator of when to water (i.e. when the yarrow starts to wilt, it is time to water). Both yarrow and clover are part of the ecolawn mix developed by Professor Tom Cook at Oregon State University.
We have used 'Micro-clover' (DLF International Seed) and strawberry clover in our trials. 'Micro-clover' is touted to be smaller, but in my experience, the size of clover depends mostly on how high and frequently you mow it. Clover can grow quite high - probably a foot or more and when it is allowed to grow, the leaves get bigger. 'Micro-clover' has white flowers and strawberry clover has pinkish red flowers. I don't think there is much difference between 'Micro-clover' and "normal" white clover (trifolium repens). They will both work.
Whether or not you use fertilizers is completely up to you. It is about making choices about how you want your lawn to look. There are some grasses that can survive better without much or any fertilizer applications (e.g. fine fescues and bentgrass). Many lawns in western Oregon naturally convert to bentgrass because it is already in the soil seed bank, it can survive long term drought like we get in western Oregon, and it can survive without any fertilizer. These are the standard maintenance practices for many people (i.e. do nothing other than mow it occassionally).
Having said that, if you don't water your lawn at all, and don't fertilize it, your lawn will lose density and weeds will encroach and you will end up with a lawn full of weeds (which is fine if you don't care about having a lawn full of weeds). However, with a little maintenance (1, maybe 2, fertilizer applications a year) and some irrigation in the summer, your lawn can maintain it's health enough to keep its density and drastically reduce weed encroachment. So, in essence, if you don't want weeds in your lawn, your choice is to make 1 or 2 fertilizer applications per year or apply herbicides fairly often.
If you don't have an issue with bees, and you don't mind the look of clover, I think it makes sense to interseed some clover in your lawn to simply reduce the number of fertilizer applications. Tom Cook, incidentally, has a colonial bentgrass lawn with clover and he rarely fertilizes his lawn. The only caveot to this is if your soil has been hauled in and it does not have an accumulation of organic matter that can release nitrogen when the temperatures warm up, you will need to fertilize for a few years until the organic nitrogen builds up in your soil.
I hope this helps. Good luck.
