Tuesday, May 26, 2015

Bird's foot trefoil vs the Strawberries

A lovely weed, commonly known as bird's foot trefoil, has invaded and is threatening to take over the bed and wipe out the strawberries at our local community garden.

Bird's foot trefoil does have a place in the garden. It is a fabulous nitrogen fixer, it makes a great warm season cover crop and it can be used with good effect as a beneficial ground cover in orchards and under tall crops such as corn. Its good qualities don't stop there! It is good for bees and it attracts beneficial insects, it can help stabilize slopes, and it is pretty to look at. However, it grows taller and much more vigorously than strawberries--so it is definitely a weed in regards to our strawberry bed.  Meanwhile, there are varieties that are much esteemed as wildflowers by the British.

"Eyebright and birdsfoot starred the grass, and already vivid green clumps of marjoram reached up to bloom." 

 John Fowles, speaking of English wildflowers in, 'The French Lieutenant's Woman.'

There are several varieties of bird's foot trefoil, the one in our garden produces 'stolons,' which are modified stems that the plant uses to spread, much like mint. When you pull the plant up, you will notice these white runners, which are just a little thicker than its stems and roots. Those are the stolons. If left in the ground or put, fresh, into the compost they will root and produce more plants. In addition, our lovely bird's food trefoil produces 'adventitious' roots--that is to say, the above ground stems can root. And as if all of that was not scary enough, after flowering it produces viable seed.

Once you learn to identify bird's foot trefoil, you will see that it is found in various places around the garden. Here is the good news. It is easy to pull, and it is easy to shake the dirt off the roots. (Please do your best to make sure the dirt stays in the garden beds. The more dirt we get into our rock pathways, the more weeds those pathways will grow.) It wilts quickly, and if pulled before it sets seed, it can be left to wilt on the edge of the rock pathways. If you have a big pile of it, spread it out, you might have to turn it over once or twice every few days before it is all thoroughly wilted. Once it is thoroughly wilted, as long as it doesn't contain viable seed, it makes an excellent addition to mulch and compost. Just remember to get it into the compost as soon as it is ready. Weeds temporarily wilting along the walk ways are all good. Leave them there too long, however, and they start breeding slugs, and after that, they start decomposing and turning into top soil. Which will encourage more weeds . . . 

If the bird's foot trefoil shows up in your own bed, or if you decide to be the strawberry hero, you are certainly welcome to bag up the trefoil and take it away. A word of caution is necessary of you are thinking of feeding it to animals. There are several species of bird's foot trefoil, some make good forage and fodder and some are considered toxic. Don't plan on feeding this to animals without taking samples to the County Agricultural Extension for proper identification first!

Meanwhile, our precious organic strawberries are imperiled, and our coordinator has her hands full with the food bank bed.

If the weather (and memory) agrees, we will try to get a photo of the bird's foot trefoil for you on Wednesday. It looks a bit like clover, with the familiar compound leaf made up of three leaflets . . . if you check the strawberry bed it is the most rampant plant in there.