Tim's Square Foot Garden FAQ's

"Population must increase rapidly, more rapidly than in former times, and ere long the most
valuable of all arts will be the art of deriving a comfortable subsistence from the smallest area of soil.
No community whose every member possesses this art, can ever be the victim of oppression in any of its forms."
President Abraham Lincoln
Address before the Wisconsin State Agricultural Society - September 30, 1859

FREQUENTLY ASKED QUESTIONS

I am having trouble finding vermiculite in my area, do you know where I can find this product?

Here is an excellent link of places to buy vermiculite, sorted by location: Where to Buy Vermiculite

How do I determine how much soil/amendments I need to fill my raised bed?

This is a very good on-line calculator to help one determine how much soil is needed to fill a raised bed. Just input the dimensions of your raised bed and it calculates the amount of soil amendments needed to fill the bed: Soil Calculator from Gardener's Supply Company

How do I determine when to start certain plants in my area? (frost/freeze dates for my area)

One of the questions gardeners always seem to have is when is the right time to start their plants. This is mostly determined by their last frost free date in the spring or their first frost date in the fall. It is important to know this as it determines when you should plant or start seeds of your favorite vegetables. Most seed packets will list the best time to either start seeds indoors or when to plant them out into the garden based on these dates (also see table below). Getting accurate frost free dates from the Internet is somewhat problematic. I did a quick search and found nearly as much inaccurate as accurate information. Here are two excellent sources of good frost free dates for the U.S. The simplest one to use is from the Victory Seed Company, found here: Frost Date Selector Page – Victory Seed Company you first select your state, then your nearest city. This should work fine for most gardeners. There is also another good source from the National Climate Data Center (NOAA) for those who want a little more in-depth information. The individual state-by-state information can be viewed and downloaded from the above Victory Seed Company link.

Using this source one can find the date and probability levels of the last 36, 32, and 28 degrees for a particular city based on climatological data from 1971-2000. To be very conservative, I would recommend that the 36 degree threshold be used (frost can still form at the surface even with temperatures above 32 degrees) along with the 50 % probability level. As an added margin of safety I would add 7 days to this date. As an example in Indiana at the “INDIANAPOLIS INTL AP” location the date of the last 36 degree day with a 50 % probability is April 29th. Adding 7 days to this gives you May 6th. In my experience, this date seems about right to me for in Central Indiana. To be extra safe, one can also use the 10% probability date without adding any days. For fall gardening I would use the first frost date (also using the 36 degree threshold with the 50% probability date), but I would not add any days to this date because most frost tolerant fall grown plants are almost fully mature by then and can withstand most frosts and light freezes.

Below is a chart that gives you the estimated amount of time that it will take to produce a transplant from seed. Take the date that is safe to transplant a specific species to your garden, subtract the number of weeks it takes to grow the transplant and then subtract the number of days it takes to germinate the seed to figure the date you should sow your seed.

Table Courtesy Harris Seeds: http://www.harrisseeds.com

SPECIES	DAYS to GERMINATE	WEEKS to TRANSPLANT
Broccoli	6-10	4-5
Brussels Sprouts	6-10	4-5
Cabbage	6-10	5-6
Cauliflower	6-10	5-6
Collards	6-10	4-6
Cucumber	6-10	3-4
Eggplant	7-14	6-7
Endive/Escarole	5-10	5-7
Kale	6-10	4-6
Kohlrabi	5-10	4-6
Leek	7-12	6-8
Lettuce	6-10	4-5
Melons	5-10	2-3
Mustard	6-10	4-6
Okra	7-14	6-8
Onion	7-12	5-6
Pepper	10-20	6-8
Pumpkin	6-10	2-3
Squash (summer & winter)	6-10	2-3
Tomato	6-14	5-6
Watermelon	4-14	3-5

Can you recommend some good performing vegetable varieties?

Broccoli: Packman
Cabbage: Golden Acre
Cauliflower: Snow Crown (better in Fall)
Cucumber: Diva
Green Bean, Bush: Derby
Lettuce: Sierra (hard to find), Green Towers, Green Ice (better in spring), Salad Bowl (better in spring), Nevada, Buttercrunch (better in spring/early summer)
Onion: Candy (recommend buying transplants and getting them in the ground in very early spring)
Shelling Pea: Mr. Big (spring only)
Sweet Pepper: Sweet Banana
Hot Pepper: Super Chili, Hungarian Wax (Hot Banana)
Potato: Yukon Gold, Red Norland

Can I use pressure treated wood for my raised beds?

No!!! Do not use any type of pressure treated wood or creosote railroad ties for your vegetable garden raised beds. They will leach out chemicals into the soil. Raised beds can be constructed using ordinary pine or rot resistant wood such as cedar. Ordinary pine is a good inexpensive wood to use, but will not last as long as other rot resistant kinds. Raised beds can also be constructed with bricks, concrete blocks, or composite plastic lumber. Prefabricated raised bed kits are also available for purchase from many garden supply companies. My personal preference is to use inexpensive pine boards, which will rot and last no more than 4 to 5 years.

How do you keep grass and weeds out of raised beds?

There is no "easy" way to do this. Perennial grass growing in raised beds should be dug/pulled up from the roots. I found the best time to do this is in the early spring just before planting time. I mostly use a hand trowel for this job. If you do a good enough job of removing the grass in the spring, you should not have a big problem with grass the rest of the growing season. Other weeds in the beds should be removed by hand as they come up. Five or ten minutes a day pulling weeds will a go a long way to a generally weed free garden. Mulching your beds after planting will also help keep weeds in check.