Store bought fertilizers contain the three most necessary nutrients in varying quantities: nitrogen, phosphorus, and potassium. When you read the fertilizer package it will say something like “10-10-10” or “5-30-10” which are simply the ratios for these three nutrients. Tomatoes don’t like too much nitrogen. If you buy tomato fertilizer from the garden center, make sure the first number is low.
Organic and homemade tomato fertilizers are better choices because they add nitrogen, phosphorus, and potassium along with other key minerals and organic matter. Choose these whenever possible.
Fish Emulsion
Fish emulsion is usually sold in powdered form or concentrated liquid. Follow package directions for proper mixing with water. Tomato plants benefit from a gentle spritz with diluted fish emulsion right on the leaves, but follow the directions—you don’t want to burn your plants. Apply the somewhat aromatic fish emulsion to your tomato plants right before a good rain or watering.
If you’re feeling really “green” you can make your own homemade fish emulsion. Find a 5 gallon bucket with a very good lid. Fill half full with fine sawdust, crumbled leaves, or shredded straw. Fill to the top with fresh chopped fish and stir thoroughly. Pour in a jar of blackstrap molasses, 1 tablespoon of Epsom salt, and about 1/4 cup apple cider vinegar. Add water to fill in the spaces. Stir this concoction daily for two weeks. Dilute with plain water in a 1:5 ratio (1 gallon of fish emulsion to 5 gallons of water). Enjoy!
Homemade Compost
Once you enter the world of creating your own compost, you’ll never go back to throwing kitchen scraps into the garbage or bagging fallen leaves and grass clippings for the landfill. Mother Nature provides you with everything you need to create great compost—this is the ultimate in recycling.
Briefly, compost is created by piling vegetable scraps, discarded leftovers, black-and-white newspaper and paper towels, fallen leaves, non-herbicide treated grass clippings, pruned stems and leaves from healthy plants, gerbil bedding, straw, and everything that comes out of the garden during fall cleanup. You can also add aquarium water if you like, for an extra bit of nitrogen. Hedge or tree twigs, sawdust, and pine needles should be added in small amounts.
Create the pile close to the garden either right on the ground or inside a wire cage. Water frequently and stir it around. In six months to a year the best compost in the world emerges, ready to feed your tomato plants. Keep two piles working so you always have some finished compost when you need it.
Do not add cat litter or dog droppings because parasites and pathogens love these family pets. Worms will live through composting and go back into your pet through the soil. Likewise, dryer lint, vacuum cleaner lint, and old cotton clothes will never decompose in time to be useful.
Manure
Animal manure has been used to grow spectacular vegetables for millions of years. Not all manure is alike: each animal’s droppings have different nutrient values, and all but rabbit manure must be thoroughly composted so it doesn’t burn your tomato plants with too much nutrition.
Cow manure
The home gardener should buy bagged cow manure at the greenhouse or garden center. Making your own cow manure fertilizer takes several years, and experts recommend waiting at least 4 months after applying homemade cow manure fertilizer before eating any of the vegetables because nasty parasites live in cow pies. Apply cow manure in the spring before tilling.
Horse manure
Horse manure breaks down much faster than cow manure, so homemade horse manure fertilizer is more within reach of the home gardener. It’s richer in nitrogen than cow manure, so apply to tomato plants in small quantities to prevent burning. Buy from a reputable stable that carefully worms its horses so you don’t spread worms through the world. Horse manure should compost for at least a year before applying it to your garden; longer is better. Apply in the spring before tilling.
Rabbit manure
This is the only type of manure that can go straight from the animal into your garden. It has little smell and breaks down quickly, delivering nutrients to your tomatoes right away. It is high in nitrogen and contains large amounts of phosphorus. The phosphorus helps to balance out the high nitrogen when applied to tomatoes.
Other Soil Amendments
Vermiculite and perlite
Vermiculite and perlite resemble little white beads and you’ll find them in most bagged potting mixes. They aren’t that helpful in the garden unless your soil is heavy and tends to stay waterlogged. Growing tomatoes in containers requires vermiculite or perlite as an amendment, however, to keep sufficient oxygen circulating around the roots.
Bone meal
Add bone meal directly into the tomato transplant’s hole before you plant. Follow the package directions but keep in mind that calcium doesn’t stick around in the soil from year to year. You’ll suffer a lot less blossom end rot if you amend the soil with bone meal calcium.
Dolomitic lime
Dolomitic lime is another source of calcium and magnesium. It also stabilizes the soil’s pH. It’s available in small bags at most greenhouses and garden centers, or talk to a lawn care professional. If you need just a little, a professional landscaper may be willing to share. Don’t use hydrated lime because it acts too fast and may burn your plants.
Sphagnum moss
Sphagnum moss should be used very carefully around tomatoes, if at all. It turns the soil acidic and adds little in the way of nutrition. If your soil is extremely heavy or mostly clay, a little sphagnum moss lightens it considerably. Compost is much better for this purpose.
Weird Tomato Fertilizers
Tomato gardeners will swear by their weird or little-known fertilizers. Don’t try to talk them out of it—just nod your head and promise you’ll try some of these methods so your tomatoes will be as spectacular as theirs.
- In a pinch, water your tomato plants at the ground with powdered milk. Don’t get the milk mixture on the leaves because it will smell horrible until the next rain. Tums (antacid tablets) are another way to add a shot of calcium to the soil. The unfortunate part about these two methods is it’s probably too late to prevent blossom end rot by the time you do them.
- If you’re lucky enough to live in an area where there are lots of lakes, there may be worm farms nearby. Ask the worm farmer if you can take some of his worm “castings” home to your garden.
- Epsom salt is an old time tomato fertilizer. It does add magnesium to the soil but little else. It also doesn’t hurt, so if you soak your tired feet in Epsom salts go back out to the garden and give the water to your tomatoes.
- Hair can be added to compost or put directly in the garden, but it breaks down very slowly and ends up matting after rain. Unless you own a hair salon, skip this type of tomato fertilizer.
- Coffee grounds and tea leaves can’t hurt, but unless you have large quantities they may not be that helpful either.