My broccoli and cauliflower have turned brown and yellow. Could I have over watered? Did frost get them? Are they dead?
Zone 5 last frost date is generally April 15, but you need to remember this is highly inaccurate.
Weather trends and observations are very important to carefully watch early in spring. Evening temperatures need to be around 50 to 55 degrees for your plants to grow well.
Did you experience below freezing temperatures or frost dangers after planting out?
If your tender young plants were exposed, most likely there condition is due to freeze.
Your season is very early yet and I would not hesitate to start again.
Here are some links to read through.
https://www.gardeningknowhow.com/edible/vegetables/cauliflower/growing-cauliflower.htm
https://www.gardeningknowhow.com/edible/vegetables/broccoli/how-to-grow-broccoli.htm
https://www.gardeningknowhow.com/edible/vegetables/broccoli/how-to-grow-broccoli.htm
My broccoli plants are thriving...larger than ever this year! But they don't seem to be forming any heads, so I'm scratching mine. Am I just too anxious? The broccoli leaves are nice and big and deep green but no heads.
It all depends - how many days has it been since the broccoli was transplanted? This may just be a matter of not waiting long enough for them to mature. Broccoli can head anywhere from 60-80 days depending on the variety.
The following article explains the reasons for "broccoli buttoning" (broccoli with small or no heads). I would review it and see if any of the information resonates with you.
https://www.gardeningknowhow.com/edible/vegetables/broccoli/buttoning-broccoli-heads.htm
I have 3 broccoli plants. One is about the size of a head of broccoli. Can I eat that? And how am I supposed to harvest? Sorry, this is my first time. Do I plant the other broccoli plants. Can you take me step by step?
Here is growing and harvesting info for broccoli plants: https://www.gardeningknowhow.com/edible/vegetables/chinese-kale/how-to-grow-broccoli.htm
https://www.gardeningknowhow.com/edible/vegetables/broccoli/bolting-broccoli-growing-broccoli-in-hot-weather.htm
https://www.gardeningknowhow.com/edible/vegetables/carrot/harvest-broccoli.htm
How does one know when broccoli and cauliflower have reached their full size?
These articles should help with that: https://www.gardeningknowhow.com/edible/vegetables/carrot/harvest-broccoli.htm
https://www.gardeningknowhow.com/edible/vegetables/cauliflower/harvest-cauliflower.htm
I have broccoli heads and I'm not sure if I should just snap them off. Also, will I get more than one broccoli head per plant?
This article should help: https://www.gardeningknowhow.com/edible/vegetables/carrot/harvest-broccoli.htm
Is there an insecticide {safe to garden} containing BT and also is good to destroy other pests for other plants besides broccoli?
In addition to using bt in the garden for worms and caterpillar pests, you can try neem oil. Both are safe to use. These article will help: https://www.gardeningknowhow.com/edible/vegetables/broccoli/worms-in-broccoli-caterpillars-in-the-broccoli-head.htm
https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm
How do I stop cardinals from eating and destroying my broccoli plants?
Two words: bird netting. Works great for many types of plant and trees.