I have a lot of the carrot family of plants growing in my garden. Above are my actual carrots, but I also grow dill, parsley, cilantro, and celery. The cilantro has been amazingly good this year. The celery seems to be growing fine. The carrots above look OK on top, but the roots just aren't growing as well. I pulled up a batch and found a mild infestation of root knot nematodes on them. Root knot nematodes can really affect a lot of crops. I tend to grow Ground Control marigolds here and there in the garden to help control them. This year I didn't start any thinking they would self sow, but only two have come up so far. So I'm going to transplant one to the middle of the bed where the fall carrots will be. Hopefully that will help.
The worst affected are my parsley plants. They struggled last year, losing a leaf or two, but this year none of the leave seem to be getting the nutrients they need. I think next year I need another variety. This one just can't handle the conditions. Also my dill which I've never had an issue with in decades, has died in the dill bed. The self seeded spot in the circle garden grew fine, but I ripped them all out when I planted the sweet potatoes. Now I might not get any seed this year. It would be a first for me. I wonder if the weird weather has made the nematodes worse.
And speaking of pests in the garden, the squash vine borer is one of my least favorite. I only grow C. moschata (butternut species) in the garden for winter squash since it is resistant. But the zucchini are all C. pepo which are quite susceptible, so the borers almost always kill my zukes when they hatch. This year I had to plant my zukes at the normal time. But with the warmer weather everything in nature is early. Which means the month of abundant zucchini is not to be unless I do something. So I finally went out and covered my zucchinis with a row cover today.
The timing for this is always a question. Traditionally you would want to do this when the chicory blooms. The chicory has been blooming for about a week. But I was not watching those. I watched the GDDs (growing degree days). For the northeast section of the US, Cornell University calculates these for us so I don't have to. Though they are calculated as follows. Take the average of the high and low for a day and subtract 50F. For instance yesterday we had a low of 73.5 and a high of 96.2, so the average of the two is 84.9. Subtract 50F and you get 34.9 for the daily number. The GDD is calculated from the beginning of the year. So each of these daily numbers is added up. When you hit 950 then the squash vine borers are out. They live for about two weeks before they die off. In New England we only really get one generation (though this year might have two).
Right now Boston is at 880. I could wait a little longer, maybe. Our weather is not exactly the same as Boston. I figured I was safe at 880 though and then I wouldn't have to pay attention as much. The fact that the chicory blossoms were out a week ago was troubling. Does Mother Nature really count degree days? I checked the zucchini stems and didn't see any eggs yet. Also the zucchini blossoms are not open yet, so I don't have to hand pollinate and the row cover won't affect anything. I'll keep an eye on it though. I see little tiny buds. I'm sure within the next week the first will open. Then I'll be hand pollinating at least every other day. Then the question will become when to take the row cover off.