Get Higher Yields Using Tomato Fertilizer
Gardeners are getting greater yields and larger tomatoes using
a variety of tomato fertilizers. There's several accepted
methods for fertilizing tomatoes and many types to choose from. I'll cover some of the most popular options.
There are reasons some gardeners prefer to use only organic
fertilizers -- they are slower acting and gentler on the environment.
Commercial inorganic fertilizers do have some advantages.
Chiefly, they are cheaper and take less effort to use.
Organic Fertilizers
Organic fertilizers, derived from plant
and animal products, are better for your garden in the long run.
Organics will never burn plants and are longer lasting, unlike inorganics
which can leach away during heavy rains. Other benefits are the improvement in
the condition of the soil in relation to plant growth (tilth), and the help to fungi which
aid plants in nutrient absorption. Common organic fertilizers
include:
- fish emulsion
- blood meal
- bone meal
- compost and compost tea
- manure and manure tea
Inorganic Fertilizers
What to avoid
Don't use high nitrogen content fertilizer on tomatoes. It
will just stimulate leaf growth at the expense of fruit. And
don't over-fertilize. This also leads to excessive green growth
and few blossoms.
Also commonly used, commercial inorganic
fertilizers are made from compounds such as ammonium sulfate or
are ground from minerals like limestone. They're rated by percentages
of nitrogen (N), phosphorus (P), and potassium (K). All commercial
tomato fertilizers are high in phosphorus, such as 5-10-5, which
is five percent nitrogen, ten percent phosphorus, and five percent
potash.
Some gardeners use both organics and inorganics at different
stages. I use 5-10-5 inorganic fertilizer in a weak water solution
for feeding seedlings once per week when
growing tomatoes from
seed in a non-fertilized soil mix. But I also use organic mulch and
compost to enrich the health and quality of my garden soil for tomatoes.
How to apply tomato fertilizer
When first transplanting into the soil
A note of caution
Whenever using commercial fertilizer, you'll want to carefully
read the label. Overfeeding or incorrect application can be
worse than no fertilizer. Also, excess runoff is harmful to
waterways.
- Prefertilize the soil a few days prior to planting. Mix
organics such as manure or compost, or a commercial 5-10-5 tomato
fertilizer thoroughly into the soil .
- After planting, water your transplants with one of the many
tomato starter solutions which are high in phosphorous. You
can make your own starter solution by mixing 2 tablespoons of
5-10-5 dry tomato fertilizer into each gallon of water. Pour
about a pint of solution on each new transplant.
- Wait to fertilize again until after the first tomato fruits
appear.
After the first tomatoes reach golf ball size
- Begin a regular fertilization program of once or twice
per month for the remainder of the growing season.
- Use one of the following
methods:
- Feed plants with a liquid fertilizer using a watering
can or hose feeder. Use commercial 5-10-5 tomato fertilizer
or make a solution of manure tea (which is made by soaking
composted manure in water, see directions on the bag).
- Or, mix dry 5-10-5 fertilizer into the soil around each
plant six inches away from the stem following the manufacturer's
directions.
When growing tomatoes in containers
- If you are using a pre-fertilized soil mix no additional
tomato fertilizer is necessary for the first few weeks.
- Begin a regular feeding program of twice per month applications
of liquid fertilzer as described above.
Time-Release Tomato Fertilizer
- An alternative, easy method for fertilizing tomatoes, controlled-release fertilizer
slowly releases nutrients for an extended period.
- Follow the manufacturers directions.
- One type uses spikes, two per plant which are pushed one-inch
into the soil 6- to 8-inches from the plant on opposite sides.
This type lasts for eight weeks. An advantage of spikes is they
can't be washed away like surface applied fertilizers.
Signs of Nutrient Deficiency in Tomatoes
Nitrogen deficiency:
- Small or light green leaves
- Very slow growth and stunted stems
- Flower buds dropping off
- Correct by applying a fertilizer high in nitrogen, such
as blood meal
Phosphorus deficiency:
- Foliage turning purple
- Small leaves
- Late fruiting
- Correct by applying a fertilizer high in phosphorus,
like bone meal
Potassium deficiency:
- Slow, stunted growth
- Fruits ripening unevenly
- Dying leaves
- Correct by adding potassium-rich fertilizer such as
potash or by mulching with organic material
Boron deficiency:
- Black areas at growing point of stem
- Stunted stems
- Abnormally bushy plant
- Correct by fertilizing with manure
Calcium deficiency:
- Upper leaves turning yellow
- Plants appear weak
- Thick, woody stems with dead areas
- Correct by spreading crushed eggshells around the plant
or applying bone meal
Magnesium deficiency:
- Brittle, curled-up leaves
- Fruit lacking in flavor
- Correct by by mixing dolomite lime or one tablespoon
of Epsom salts into the soil