Fertilizing tomatoes is all about knowing:
If you want to grow great tomatoes, this is important knowledge because...
Considering how rapidly tomato plants grow from a tiny seed to a large plant pumping out pounds of fruit, it’s no surprise that they have a keen appetite.
So if you want your tomato plants to supply you with lots of lip-smacking tasty tomatoes, you’ll need to supply them with the nutrients they require to do their job.
Combine our general guidelines for fertilizing tomatoes with your knowledge of the fertility of your garden plot to devise the perfect plan for fertilizing your tomatoes.
(You did test your soil when you were preparing your garden soil, right?)
Recommending a specific fertilizer for your tomatoes is a bit tricky because it depends upon the fertility level of your soil. And not just the overall fertility level, but also the level of specific nutrients your soil contains (your soil test will give you that info).
But in general, choose a tomato fertilizer with a lower nitrogen number (the first number), a high phosphorus number (the middle number) and a high to moderately high potassium number (the last number).
So a fertilizer analysis such as 8-32-16 or 5-10-10 should work well for you.
It's best to avoid high nitrogen fertilizers with tomatoes. Excess nitrogen will result in lots of tomato foliage with very little tomato production.
Also avoid using a general-purpose fertilizer or lawn fertilizer. These aren’t balanced properly for tomatoes. And avoid ammonia-based fertilizers.
Your best bet is to buy a fertilizer that is blended specifically for tomatoes.
If you’re using organic fertilizers rather than blended synthetic fertilizers, be sure that you’re giving your tomato plants the proper balance of nutrients: low nitrogen, high phosphorus and high to moderately high potassium.
You can also buy organic fertilizers blended specifically for tomatoes.
Certain animal manures make great garden fertilizers, but you have to be careful about how you use them.
Never apply fresh manure to growing plants; you’ll do much more harm than good. If you have fresh manure to use, incorporate it into your garden plot several months before planting.
Composted manure is fine to apply at any time.
Again, it’s a bit difficult to give absolute specific recommendations for the quantities of tomato fertilizer you should apply because it depends upon your soil.
And an additional variable is the varieties of tomato plants you’re growing. Obviously, a dwarf plant that grows to just 18 inches will need far less tomato food than an indeterminate that will ultimately reach a length of 18 feet.
But in general, plan on applying about 1 to 2 tablespoons of a balanced tomato fertilizer per plant with each application. Apply the fertilizer as a side dressing (sprinkle around the perimeter of the plant about 6 inches from the stem).
If you’re using a fertilizer blended specifically for tomatoes, the labeling of the fertilizer package will likely give you specific recommendations for the amount per application.
Organic fertilizers tend to be pound-per-pound lower in nutrients than synthetic blended fertilizers, so you’ll likely need to put out more per application.
You’ll incorporate some fertilizer in the soil when you’re planting your tomatoes. That’ll hold them for a while. But the hungry young plants will soon need more food.
Plan on fertilizing tomatoes about every 2 to 3 weeks, but you’ll need to modify this schedule based upon the soil type of your garden.
If your garden soil is sandy, you’ll need to fertilize more frequently because the nutrients will be rapidly leached out of the soil by rainfall and irrigation.
If your garden soil has lots of clay, you’ll be able to get by with putting out tomato fertilizer less often, because clay soils tend to hold nutrients longer.
Pamper your plants, give them the tomato food they need in adequate quantities, and both you and your plants will be happier in the long run.
Feed your tomato plants with the nutritious food they need to be productive, and they’ll return the favor by feeding you a bumper crop of nutritious, tasty tomatoes.
That’s a fair deal, wouldn’t you agree?