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sandpapertongue

When to fertilize tomatoes?

9 years ago

My tomatoes (Mr. Stripey, Cherokee Purple) are over a foot tall now and starting to form flower buds. When do you give some plant food? Are you supposed to wait until after the tomatoes have formed?

Comments (8)

  • 9 years ago
    last modified: 9 years ago

    No, the plants need fertilizer starting around the 10-15 day mark from germination, in very small amounts, when the seed no no longer can supply the minerals needed for healthy growth. But you need to specify the fertility of your growing mix as devoid of fertilizer or what amount it contained ... the soil or medium they are currently in. If your mix contained fertilizer you may be ok, but if the amount is light, get ready to increase nutrition while the plants blossom and set fruits, to insure your living tomato factory has the raw minerals it needs to produce tomatoes.

    Cheers

    PC

  • 9 years ago

    Thank you, there's so much I don't know! This is my first year with raised garden beds, I have 2 4x4 beds that were filled with 1/3 peat, 1/3 compost and 1/3 soil. The tomatoes I bought from a nursery were already young plants, no blooms but close to 1' tall. I have one tomato in each bed.

    I have grown tomatoes before in another part of my yard and while the cherry tomatoes were fine, all my bigger ones are always really small. I am also growing strawberries in the same bed and they are pretty small too. I don't expect to get gargantuan grocery store sized fruits, but I thought maybe some liquid fertilizer would help things along.

    But then I thought I heard something about not giving fertilizer (or at least a N heavy one) before the plants have fruited because then you'll just encourage growth of leaves? So I've always been nervous fertilizing my plants and usually just go with a dose of compost every year.

  • 9 years ago

    Compost is a soil amendment, not a fertilizer. A source of nutrients the plants can actually use is necessary and many options are available.

    Different plants have different needs and have different needs at various stages of growth too. So it isn't a one time per season issue.

    It is important for success for the grower to understand those needs by doing some research on them. When one mixes different plants in the same small bed it is especially important to understand those differences. In your particular situation the berries and tomatoes are fairly close in needs so a general, full spectrum liquid used per label directions should work ok.

    Dave

  • 9 years ago

    Thank you Dave! One more question, do you fertilize regularly through the growing season then?

  • 9 years ago
    last modified: 9 years ago

    Liquid fertilizers require continuous application because the dosage is low at any given time, to avoid burning the plants, and then the liquid (soluble types like Miracle-Gro) fertilizers get washed away in the rain. Buy a Miracle-Gro tomato 18-18-21 formula and use as directed if you want the answer that takes up the least space :-).

    As mentioned by Dave, strawberries and tomatoes have similar tastes in type of fertilizer, though tomatoes eat and drink a lot more.

    Cheers

    PC

  • 9 years ago

    "One more question, do you fertilize regularly through the growing season then?"

    The general answer is yes as the plant is using up the nutrients as it grows.

    How often all depends on the type of fertilizer you use which is why label directions are imnportant. With dry/granular ferts they normally get a dose mixed into the soil before planting, a side dressing with another dose right after first fruit set, and another long about mid-season. If you have an extra long growing season as you and I do they can also use a fourth dose side-dressing about 6 weeks later to hold them until frost.

    With liquid supplements they are fed more frequently as PC said. Usually every 10-14 days depending on the fert you choose.

    This is for inground plants, not container plants. Container plants have to be fed weekly in most cases when using liquids and every two weeks with granular.

    I recommended liquid ferts above since you have mixed crops in the same small area and mixed perennials with an annual - for future reference that's not a great idea ;-). The liquids are easier to spot feed specific plants. For example, if you over-dosed your berries with the nitrogen the tomato needs early on then you'll get big berry plants but few berries.

    Dave


  • 9 years ago

    I usually use the "look" of my plants to tell me if they need fertilizer. I fertilize until the leaves are that nice dark green color I like and than try and keep that same pace until they about full grown, then I back off a bit.. Tomato plants definitely need fertilizer and plenty of it. I have had an underfertilize bias for most of my life. Not sure where the fear of overfertilizing came from. A few years ago I fertilized my tomato plants with lots of calcium nitrate, and the leaves were super dark green and large, but it still also flowered just fine with super bright yellow flowers, and produced plenty of tomatoes. So, yes, don't be afraid to feed them, they will respond.