Get some Tomato Tone fertilizer (organic, easy to use) and feed the plants every few weeks as directed. Weed those beds and put down mulch of some kind like straw or seedless hay. It’ll help prevent weeds from regrowing and retain moisture in the heat.
Keep them watered consistently; tomatoes will get stretch marks or other deformations if not watered on a schedule of some sort. I’ll water every other day as needed if it hasn’t rained.
Tomatoes are ready to harvest when they blush, or show signs of pink/re on the bottom. You can then bring them inside to fully ripen on the counter. This serves two purposes: it prevents bugs or critters from eating your hard earned work before it fully ripens and prompts the plant to produce more flowers, thus more fruit.
If I don’t pull my tomatoes when they blush, the bugs destroy them very quickly. Most tomatoes are ready to eat when deep red, unless you’re growing a yellow variety or want to eat fried green tomatoes and pull them early.
One last tip: cut any “suckers” that grow between branches. A quick YouTube search should demonstrate. Cutting suckers focuses growth into the fruits instead of more plant.
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