If you want to start your planting early, before the last frost, you may want to consider creating an inexpensive hoop house. Hoop houses protect your seedlings from frost and cold winds, thereby extending your growing seasons sometimes by months. Hoop houses vary in size from very small in backyards to enormous, such as the ones you see at commercial nurseries.
The hoop house I have is for one of my 4 x 8 raised beds (see http://www.aihd.ku.edu/gardens/raised_bed_garden.html )
Four 10 foot lengths of ½ inch diameter PVC pipes ($1.20 each at Home Depot)
Eight 2 feet-long ½ inch diameter rebar. Or, 4 four-foot lengths then use a hack saw to cut them in half. $2.58 ea. At Home Depot
12 large binder clips. I got my box of 12 at Office Depot for less than $4
1 roll of plastic drop cloth. A 10x20 roll for 3.49 at Home Depot. Many experienced hoopers will tell you to buy more substantial plastic, but I want to see what kind of weather this inexpensive plastic can handle.
With a heavy metal blade in your hacksaw, you can cut through the ½ inch rebar in a minute or less.
Drive one of the 8 pieces of the rebar into the ground at each corner with a hammer or mallet, then again at 32 inches and 64 inches on each side until five inches of the bar is left above ground. Simply fit one end of the PVC pipe over one rebar then bend the pipe so it fits over the rebar on the opposite side.
Attach one end of the plastic drop cloth at one end with two clips, then bring the cloth over the ribs, attaching with clips at the base of each rib. I put some extra metal t-posts at the ends of the raised beds to keep the plastic from flying up, and an 8-foot wooden post along the side.
Inside this hoop house are rows of lettuce, broccoli, spinach, cauliflower and radishes. I planted them on March 17, 2009 and will check regularly to see how they’re doing.
I bought this smaller “Mini Hooper” hoop house from http://www.newdimensionseed.com/toolsminihooper.html. It cost considerably more and is much smaller than what I paid to create one myself.
Inside this Mini Hooper are my pepper seeds (from Pepper Joe’s): Pepper Joe’s cayenne, crimson torpedo, sweet crimson, ancho/pablano and Tobago seasoning pepper.
My small hoop house is very simple and I will find out pretty quickly if it is strong enough to withstand the Kansas spring winds and storms. Hoop houses are often much larger and complicated such as the expensive mail-order one we put together (with $400 worth of additonal materials) that was truly a pain to build. Still, it was somewhat worth it. When it was 20 degrees outside, it remained much warmer inside:
You can access some photos from inside the house from my blog: http://www.aihd.ku.edu/blogs/october20.html
More information about hoop houses:
Mother Earth News: http://www.motherearthnews.com/Organic-Gardening/2003-02-01/Hoop-Houses.aspx
Mini Hoop House: http://www.noble.org/Ag/Horticulture/MiniHoopHouse/index.html