Most of our experiments are harvested for the year so we’re turning our focus to several greenhouse experiments. In order for us to study weeds in the greenhouse we need seed and unfortunately it is not as easy to come by as crop seed. Even the internet has not helped weed scientists in their pursuit of seed. Try searching “weed seed” sometime and you’ll begin to see some of the problems. There are a two places that sell weed seed that we use occasionally, one in the US and one in the UK. The problem with buying seed from these sources are a) it is expensive and b) the seed is from weeds that are not grown in Michigan so they may exhibit slightly different characteristics (i.e. they are different biotypes). This leaves us with one option, collect and clean our own seed. Some weed seeds are very easy to collect and clean, like velvetleaf which produces its relatively large seeds in a capsule and field pennycress which also produces seed in a capsule. Other seeds are hard to separate from the plant (e.g. ragweeds), super small (e.g. common chickweed), dispersed too quickly (e.g. some asters), protected by spines (e.g. cocklebur), housed in berries (e.g. eastern black nightshade), or some combination of these undesirable traits. After you have collected and cleaned your weed seed you have to worry about getting it to germinate, but I will save those woes for another day.
Yesterday some students collected common pokeweed berries for us and today I am working on cleaning the seed. Here are a few photos from the process.