Software tells when to plant each variety of vegetable in every region

Q. I’m a programmer and I also am a gardener. I have a couple ideas for computer programs that are garden related.

However, to write the programs I’m thinking about, I need more
gardening information than I have in my hands. (I already own
GardenMaster and the growing manual and the other books that came with
it.)

What I am really needing the most to get started is dates for planting, maturity/harvest, etc., etc. All the information really
needs to be for every region is the program I’m thinking about could
be used for everyone (not just ppl in my region.)

I’d also be interested to know what regions can get 2 spring/summer
plantings (and what plants actually can have 2 sessions) and how to
determine when the first then the second should be planted.

I guess, is there one central source such as a gardening encyclopedia
or gardening bible?

A. I believe you already have the program you’re thinking of writing. It’s called the Garden Master CD, and it’s available here https://foodforeveryone.org/garden_master/). Meanwhile I’ll answer your questions below.

There are two major elements to the decision making process as to when to plant, and if or when a second crop can be planted.

The first factor is the last spring frost date and the first fall frost date in the area you’re considering. The growing season lies mostly within that time period. The Garden Master CD has a database of about 3,000 areas in the USA with their Average First & Last Frost Dates.

The second factor is the plants themselves. There are four “types” of plants with regard to their levels of frost tolerance:

1. Hardy, or frost tolerant – can be planted 3-4 weeks before the average last frost date (ALFD) of the spring.

2. Semi-hardy – can be planted 2 weeks before the ALFD

3. Frost sensitive – can be planted safely ON the ALFD.

4. Frost intolerant – can be planted safely 2 weeks AFTER the ALFD.

We also have a schedule of plants and their level of frost tolerance on the Garden Master CD, and this is used to give the GM CD software the ability to tell people anywhere in the country the exact day to plant their crops, no matter which one they are considering.

Seed packets and seed catalogs also give the days to maturity of each variety. And there can be significant differences in maturity times, even between different varieties of the same species. For example, there are tomatoes that mature in 55 days and some that take 85 days. So you need to have that information for the specific variety as well, in order to determine whether or not two crops are possible.

To determine if a second crop of something is possible, just check the days to maturity and the days to the first expected fall frost. Of course most people plant a second crop of cabbage (as an example) after the corn is finished, or whatever. It’s usually not the same crop back-to-back in the same beds.