Q: How do I get rid of sandburs in my yard?
A: I have received many questions this month about getting rid of weeds but the main problem has been the maturity of these weeds. It is very difficult to kill adult, seed producing weeds in lawns. The time for treating weeds is when the plant is very small, when it is easier to manage. We have very few chemicals in our arsenal that will kill mature, reproductive weeds.
Ideally, we should be taking care of our lawns to reduce the number of weeds. Proper care of lawns means strong healthy, nearly weed free lawns. First, we should fertilize using 15-0-15, Nitrogen, Phosphorous, Potassium, respectively. I know as Americans we feel if 15% Nitrogen is good, then 30% or 50% would be better – not necessarily. Balance in everything, including lawn fertilizers. Fertilization should occur in March, May and September but NEVER in the summer months.
Irrigation is also essential in maintaining a healthy lawn. Water lawns 6-10am about ¾ to 1 inch of water. You will need to measure your sprinkler output. Put out empty cat food or tuna fish cans (10-15) at a zone and run your system. After 20 minutes, stick a ruler in the cans and measure your system’s output. Run your sprinkler system until it reaches the ¾ to 1 inch so you know how long you need to water your lawn. Do not add lime to the yard unless a soil test dictates the need for lime.
Now to get back to the sandbur problem; you could use a product called IMAGE but it must not be used in cold or hot weather and there are several don’ts when using this product so please read and follow label directions. But the best advice I can give you is to get rid of the seed heads (the stickers) on the weeds and apply a pre-emergent herbicide next year to prevent the seeds from germinating.