How Late Can You Put Plants Outdoors and Still Get a Harvest?

I had an E-mail about starting plants later in the summer, but the sender did not want his actual E-mail used on the blog… The sender had started some seeds indoors and life had gotten complicated and the plants were still in small pots under a fluorescent light on/off - 20/4. It is late June and the first frost won’t be until early October, assuming a normal year.

It is a great idea to start your plants indoors for an outdoors garden.  You can still put your plants out in late June or even a bit later in the summer. The problem is your plants will be smaller so you will get less of a yield. It would still be great to put out a tomato or pepper plant in July and only get 2-3 peppers than throw the plants on the compost pile and get no peppers.
Some things to keep in mind... If the plants are root bound, you will want to break up the roots to they do not keep growing around in circles. Some people suggest using a clean sharp knife and making 3-4 incisions along the sides. I tend to break the bottom of the root mass up so the roots grow down.
You will also want to keep the plant watered well, one because you will damage the roots when you break them apart but also secondly in your situation I assume the plants have a pretty small root system compared to the above ground biomass. It will take a couple weeks for the roots to grow deep enough to support and supply the plant with water.
You may also want to space your plants CLOSER together since they will not get as big as normal. When growing indoors, it is possible to increase yields by growing lots of smaller plants vs. a few large plants. I do not know if this is the same for outdoor growing, since plants do not have the special limits they do indoors it would be better to start plants early and have them get as big as possible.
You may be tempted to add a high nitrogen fertilizer, but this may lead to the plant growing vigerously in vegetative mode and you may not get flower/fruit set. I would still give the plant some nitrogen, but I would recommend the phosphorus be the highest number.
Good Growing,
Dr. E.R. Myers