Yellow Foxtail
Gardening Question From Reybo:
This spring I bought from an online garden center 5 lbs of wildflower seed. It should have gone to a larger site than 15 x 30 but that’s where it went. It’s been more than 60 days and it’s become a weed patch, 98% Yellow Foxtail and the rest Zinnia, plus a few others. I’m going to wipe it all out with a weed trimmer, then 50% acetic acid (garden strength vinegar.) But how did the weed contaminate the seed to such a massive extent? The supplier refunded my money but at my age, there are few summers left make a butterfly patch.
Answer From Pat:
Not sure where you live but in Southern California where I live and most areas of the West the correct time to plant wildflowers is autumn. I plant mine in November to take advantage of the rains. They begin blooming in late February and last through June or even longer if I include some summer-blooming wildflowers in my mix.
In regard to weeds, I am not sure where you purchased your seeds but my experience with most purveyors is that the seeds are mostly weed-free. Secondly, as you mentioned you purchased too much seed.
Thirdly, could it be possible that the weed seeds were already in the ground waiting to sprout when you began watering to germinate your seeds? Sometimes when people dig too deeply prior to planting wildflowers, they dig up old weed seeds that have been buried for years. Best way is to simply to sprinkle the seeds on prepared ground and rake then lightly into the ground, though this won’t work with garden varieties of zinnia. Maybe you ordered the wild zinnias and that’s okay since they grow like any other kind of wildflower.
Also, I am not sure that vinegar will effectively kill these weed seeds. I’m pretty sure it won’t work. Another possibility is to use an organic pre-emergen herbicide such as “Preen” according to package directions to kill the weeds this year and then try again next year to plant your wildflowers after purchasing the seeds in individual packets from a reputable purveyor and make your own mix. After using Preen you will need to let rains and winter weather wash it away or it will prevent your wildflower seeds from germinating. Not sure how many months you will have to wait. Another way is to water the patch to germinate all the weeds. Then weed-wack before they bloom and bear seeds and clean up all the residue.
The third way is “Solar Sterilization” and is the best and safest of all. You need to purchase a roll of clear plastic used for agriculture and some pins to pin it down or cut up old wire coat hangers from the cleaner and use those. You must first soak the ground really well to get it wet to the depth of about 8 inches or one foot. Then cover with clear plastic and pin it down flat. This is called “solar sterilization”. The heat of the sun in summer and early fall will safely kill the weed seeds in about one month or six weeks of hot weather. That would cure your problem and it will not hurt the seeds you plant later this fall or next spring.
I hope you will live many years so you can enjoy wildflowers many years into the future and also the butterflies they bring. I am old too but luckily to have good genetics and a healthy lifestyle and I never smoked. I suppose I might make it to100. It’s not that I particularly want to live that long, but many people do these days so I might have no control over it. Family, friends, and growing wildflowers make life worthwhile. I think the formula for a happy life is: “Something to love, something to do, and something to look forward to.”
Photo by gabepopa 
I have just read all the post about foxtails I have been living at a friend’s home for about 7 months and have a German Shepard, My friend has a Jack Russell ~ Anyway her backyard is nothing but foxtails and they are all dry and all over the backyard. I have tried to clean them up raking & sending them out with the yard waste. But I am really worried about our dog’s and would love to rid the yard as soon as possible of the foxtails. HELP WHERE DO I TURN & WHAT DO I DO ???????
Thank you for your time
Kathi in Northern California
I suggest pull out or hire someone to pull out and rake up all foxtails, area by area. Then dig up and cultivate all ground or rototill. Apply pre-emergent organic weed control on top of cultivated soil and continue at correct times of year and even more often. Read and follow all directions. Then cover all bare ground with heavy layer of mulch to keep weeds down. (tree-trimmers chopped up leaves and wood works fine. (Do not dig this into ground since it will rob nitrogen from the soil in order to rot.) An additional step you might try if desired is to put down landscape cloth under the mulch. Another way often done in France is to lay landscape fabric and then put a 2 or 3 inch layer of gravel on top to use as open areas. Gravel is good for dog’s feet—it makes them compact—, however, it may slide downhill on slopes, so it’s best for covering terraces. Fine to put garden furniture and umbrellas on top of the gravel and use like a patio.