In the article Growing Sugar Snap Peas in a Container, I commented on the variety I selected being cold tolerant down to 28 degrees. I inadvertently tested that claim. I have the peas growing in 12" x 18" grow-boxes on the patio. I cover them with gardening fabric at night. Well, I took off for the evening without covering the peas. A fast moving snow storm rolled in and dumped three inches of snow on the ground - including my patio. The peas sat in the dark under that cold blanket of snow for four hours before I got home. I looked at the snow covered peas and was sure it was colder than 28 degrees and that I had killed them. I quickly brushed the snow off the peas and covered them for the night - hoping for the best and fearing the worst. Well, the new day dawned bright but cold. After a few hours the patio had warmed up to 38 degrees. So, I took the cover off the peas to find them tall, perky and no worse for having been smothered in snow. It's wonderful to grow a vegetable plant tough enough to survive my neglect.
An early March snow storm reminded be of why I love container gardening. The last week of February I planted sugar snap peas in 5 1/2" x 12" x 18" ceder grow-boxes. I chose a variety of sugar snap peas that grow 24" tall, doesn't need to be supported and is cold tolerant down to 28 degrees. The seed package indicated the seeds would sprout in 7 to 14 days. I was hoping to do better than that so I placed two of the grow-boxes on a heated seed starting mat. I put a third grow-box on a shelf in front of a south facing window. Using the seed sprouting mat the peas were up and going in 4 days. The grow-box in the window had peas up and going in 6 days. The grow-boxes are small enough they are easy to move if necessary. Now that the peas are about 4" tall, I'll leave them outdoors and just cover them at night with gardening fabric. If we get more snow I'll move the grow-boxes onto a covered porch. I hope to be eating fresh garden peas by the middle of April.
Many of us have plants growing in window boxes in our houses. I have garden greens that are doing well, as long as I remember to water them.
If you keep the window box in a spot where you see if often, it is no big deal to water it. But if you have several boxes, or if you keep them in a room off somewhere, it is easy to neglect the plants.
This article describes an easy way to make a self-watering box using inexpensive materials you can find at a hardware store.
The system puts a reservoir of water under the potting soil. A wire rack covered with felt supports the soil above the water. Water can filter down through the soil and into the reservoir below.
A small pump circulates water from the reservoir up into the soil. The pump can be put on a timer so it automatically circulates for a pre-set time every day.
The system could easily be modified to water several boxes.
It is worth considering if you are getting serious about indoor grow boxes.