Brussels sprouts are heavy feeders, so they need a rich organic soil of aged manure and compost. (There can almost never be enough!) They tend to do best in cool weather, from the time they are set out to the fall, when a frost sets on them. You also need to check the soil pH; it should be more or less in the middle. The hot weather (yes, it’s summer, it’s going to be hot) may have slowed them down but I/we suspect it’s a soil-based problem. We’ve experienced it too. You could try to amend the soil as soon as possible and see if you see any change but it may be too late to expect a luscious golf-ball-size sprouts.
Brussels sprouts are heavy feeders, so they need a rich organic soil of aged manure and compost. (There can almost never be enough!) They tend to do best in cool weather, from the time they are set out to the fall, when a frost sets on them. You also need to check the soil pH; it should be more or less in the middle. The hot weather (yes, it’s summer, it’s going to be hot) may have slowed them down but I/we suspect it’s a soil-based problem. We’ve experienced it too. You could try to amend the soil as soon as possible and see if you see any change but it may be too late to expect a luscious golf-ball-size sprouts.