May is honestly one of my favorite months in the garden. The weather is warming up, and tomato plants are really starting to take off — which means it’s the perfect time to think about what you’re feeding them.
The right nutrients at this stage can make a huge difference in how your plants grow and how many tomatoes you end up harvesting. Some of these feeding options might even surprise you!
1.) Compost Tea
Compost tea is basically liquid gold for your tomato plants. You make it by steeping finished compost in water for 24 to 48 hours, then straining out the solids. The result is a nutrient-rich liquid packed with beneficial microbes that your soil will love.
Apply it every two weeks in May, either as a soil drench around the base of your plants or as a foliar spray. It works well in all zones and gives your tomatoes a nice, steady boost without the risk of burning roots.
2.) Fish Emulsion
Fish emulsion is a liquid fertilizer made from processed fish, and it’s one of the best things you can give your tomato plants in May. It’s packed with nitrogen, which helps your plants grow strong stems and full, green leaves during those early weeks of the season.
Just mix it with water according to the label and apply it around the base of your plants every two to three weeks. It smells pretty bad, but your tomatoes will love it.
3.) Epsom Salt
Epsom salt is a gardening classic for a reason — it’s packed with magnesium and sulfur, two nutrients that tomatoes absolutely love. A magnesium boost helps your plants produce more chlorophyll, which means better photosynthesis and stronger overall growth during those busy May weeks.
Mix one tablespoon of Epsom salt into a gallon of water and apply it as a foliar spray or soil drench every two weeks. It works especially well if your leaves are starting to yellow between the veins — a classic sign of magnesium deficiency.
4.) Bone Meal
Bone meal is a slow-release fertilizer made from ground animal bones, and it’s packed with phosphorus and calcium — two things your tomato plants really need in May when they’re starting to set roots and build strong stems.
Work it into the soil around the base of each plant, about a tablespoon per plant. It breaks down gradually, feeding your tomatoes over several weeks.
It works best in slightly acidic soil, which is right where tomatoes like to be anyway.
5.) Kelp Meal
Kelp meal is a dried seaweed fertilizer that works really well for tomatoes in May when they’re just starting to take off. It’s packed with trace minerals, natural growth hormones, and a decent amount of potassium — all things tomatoes love during their early growing stage.
Work it into the soil around your plants at about one to two cups per plant, or mix it into your potting soil before planting. It breaks down slowly, so it keeps feeding your tomatoes for weeks without any risk of burning the roots.
6.) Coffee Grounds
Don’t toss those used coffee grounds — your tomato plants will thank you for saving them. Sprinkle a thin layer around the base of each plant in May, when the soil is warming up and your tomatoes are really starting to grow. The grounds add nitrogen to the soil, which helps plants produce healthy green foliage.
Just don’t go overboard. Too many coffee grounds can make your soil too acidic. A light application every few weeks is plenty.
7.) Crushed Eggshells
Crushed eggshells are one of those things you’d normally toss in the trash, but your tomato plants will thank you for saving them. They’re packed with calcium, which helps prevent blossom end rot — a common problem that shows up in early summer when plants are growing fast.
Work them into the soil around the base of your plants in May, before the growing season really picks up. They break down slowly, so the benefits last all season long.
8.) Worm Castings
Worm castings are basically worm poop, and your tomato plants absolutely love them. They’re packed with nutrients and beneficial microbes that help roots absorb food more efficiently. Best of all, they won’t burn your plants even if you go a little heavy-handed.
In May, work a handful or two into the soil around each plant or mix them into your watering can as a liquid feed. They work well in containers and garden beds alike, giving your tomatoes a steady, gentle boost all season long.
9.) Alfalfa Meal
Alfalfa meal is one of those old-school garden amendments that serious tomato growers swear by. It’s packed with nitrogen, potassium, and a natural growth stimulant called triacontanol, which helps your plants produce more energy and push out new growth faster.
Work it into the soil around your tomato plants in May at about one cup per plant. It breaks down slowly, so it keeps feeding throughout the growing season without the risk of burning your roots.
10.) Banana Peels
Banana peels are something most of us toss without thinking, but your tomato plants will thank you for saving them. They break down and release potassium into the soil, which helps tomatoes develop strong roots and produce more fruit through the growing season.
You can bury small pieces of peel near the base of your plants or soak them in water for a few days to make a simple liquid feed. Either way, May is a great time to start using them regularly.
