Your soil pH is another very important part, tomatoes grow best in soil with a pH level of between 5.5 - 7.0 for the giants I recommend soil pH level of 6.5 - 6.8. The pH level of your soil indicates its relative acidity or alkalinity. A pH test measures the ratio of hydrogen (positive) ions to hydroxyl (negative) ions in the soil water. When hydrogen and hydroxyl ions are present in equal amounts, the pH is said to be neutral (pH 7). When the hydrogen ions prevail, the soil is acidic (pH 1 to pH 6.5). And when the hydroxyl ions tip the balance, the pH is alkaline (pH 6.8 to pH 14). Always, always, always check your soil pH never guess, pH testers are very cheap from most garden and nursery centres around $5.00 for test kits with capsules, I myself prefer the $10.00 pH meter. Stick it in, read it, your done. If you do have to amend your soil do the following.

If the pH level of your soil is less than 6.5, it may be too acidic for optimum growing of giant tomatoes. The most common way to raise the pH level of your soil (make it less acidic) is to add powdered limestone. Apply it in the fall because it takes several months to alter the pH. Wood ash will also raise the pH level, and it works more quickly than limestone and contains potassium and trace elements. But if you add too much wood ash, you can drastically alter the pH and cause nutrient imbalances. For best results, apply wood ash in the fall, and apply no more than 2 pounds per 100 square feet, every two to three years.

To raise the pH level of your soil by about one point:
- In sandy soil: add 3 to 4 pounds of ground limestone per 100 square feet.
- In loam (good garden soil): add 7 to 8 pounds per 100 square feet.
- In heavy clay: add 8 to 10 pounds per 100 square feet.

If your soil is higher than 6.8, again it won’t be an optimum area to grow giant tomatoes you will need to acidify your soil. Soil is usually acidified by adding ground sulfur. You can also incorporate naturally acidic organic materials such as conifer needles, sawdust, peat moss and oak leaves.

To lower soil pH level by about one point:
- In sandy soil: add 1 pound ground sulfur per 100 square feet.
- In loam (good garden soil): add 1.5 to 2 pounds per 100 square feet.
- In heavy clay: add 2 pounds per 100 square feet.

Crop rotation is another big plus when growing these giants from year to year, however for most backyard growers rotation of their crops is not available, there just isn’t enough space especially where tomatoes are concerned since you need to keep these near the back northern most part of the garden as not to shade the rest of your crops. Even if you do not fit in this category because either you don’t grow other crops or you have adequate space for crop rotation keep reading before going on as I’ll explain how to amend your soil with nutrients.

To amend your soil to put back the needed nutrients your tomato plants will need every year, do the following. By the way the best time to do this is in the fall. Remove 12” of soil from the tomato beds using a 5 gal pail, put it in a pile to the side of the bed, once you have taken 6 full pails out then add 3 full pails of compost and 1 pail of well aged manure, continue the process until all the top 12” of the soil is removed, roto-til the lower 12” and pile back in all the soil, compost and manure sitting beside the bed, then roto-til this top 12” and then add about 2” to 3” of leaves to the top of the bed to tuck it in for the winter.

As well, before the leaves are put on check the soil pH to ensure the range is between 6.5 - 6.8 if not add amendments as discussed earlier, again this is preferred in the fall rather than the spring and remember you can't, and shouldn't try to change the pH of your soil overnight. Instead, gradually alter it over one or two growing seasons and then maintain it every year thereafter.