We vacationed for a month and returned to find a 5-foot tall weed. I keep waiting for it to flower to help identify it, but the flower buds just sit there unopened.
This is American burnweed, and you’ve noticed the most interesting thing about it: the flowers don’t have petals. They seem to never mature, yet the flowers are pollinated by wasps. The resulting ball of wispy achenes, each with a seed at the end, are similar to dandelion puffs and also are dispersed by wind. An annual weed that prefers moist sites, it’s obvious why we’re seeing more burnweed this year, but it is not a rampant weed. It pulls easily to prevent spread.
In my otherwise healthy sunny lawn, numerous brown patches have been showing up. The grass in those patches is totally dead, with no sign of fungus spots. Digging under a portion shows no roots at all, but also no grubs. We have been getting very frequent, very heavy downpours of rain. The grass is almost never dry and the underlying ground is constantly saturated. What might be causing these patches of grass to die?
You have solved this yourself. The wet soil underneath the dead patches is the likely cause, rotting the roots. Grass roots do not like to sit in wet soil for an extended period of time. When the soil dries out enough, reseed. Search “lawn renovation” on the HGIC website. “HG102: Lawn Establishment, Renovation and Overseeding” is a good guide to success. Consider addressing the wet soil issue if it’s a yearly problem.
University of Maryland Extension’s Home and Garden Information Center offers free gardening and pest information at extension.umd.edu/hgic. Click “Ask Maryland’s Gardening Experts” to send questions and photos.