My tomatoes grow non-stop in low sunlight with no extra fertiliser - experts explain how

My mum has a bit of a plant obsession. Every time we pop to a garden centre or a supermarket, we always leave with a new potted plant, but our gardening conditions couldn't be worse for growing healthy and thriving plants. My garden is quite small, under renovation, and we have a massive tree that blocks the sun right outside our fence that we cannot cut down.

Despite all the forces against us, we have successfully grown an abundance of tomatoes, bell peppers, and cucumbers (even if the plant looks half dead). When I ask my mum how she successfully grows our tomatoes, she jokingly says: "With plenty of water, and a beautiful song." But it's true, we only water our plants a few times a week and add no fertilisers - and as a garden writer I know this leaves room for failure.

Curious to know how our conditions can grow and produce a respectable harvest, I reached out to several gardening experts for their input.

Can tomatoes grow well in partial sunlight?

Stephen Kohley, a floral and gardening expert and the owner of Sonny Alexander Florist & Flower Delivery says: "Growing tomatoes with minimal sunlight (like four to six hours) daily is totally doable, but it's all about how you manage their care and make sure they're hydrated. To have a solid tomato garden with partial sunlight, I would choose smaller tomato varieties or determinate types that aren't as needy when it comes to sun. Always place them where the midday sun hits strongest and cut away the lower leaves to improve fruit production up top."

To grow bigger, juicier tomatoes in partial sunlight, Stephen suggests giving each plant plenty of space to boost airflow and watering deeply but less often to promote strong root development.

Remove suckers regularly so the plant can channel its energy into producing fewer, but healthier, fruits. Companion planting with herbs like basil or flowers like marigolds can also support growth by attracting pollinators and deterring pests.

Loren Taylor, a seasoned expert in landscaping and gardening and the owner of Soothing Company, said: "Tomatoes can surprise you with how well they grow, even when they do not get sun all day. I have had beautiful, full harvests from gardens that only get four to six hours of direct light. The trick is to work with nature instead of against it.

"The first thing I look at is the type of tomato. In partial sunlight, I choose smaller ones like cherry or saladette tomatoes. They ripen faster, need less energy, and still give you that burst of flavour. I also plant a few more than I would in full sun so I still get a big harvest overall."

Do tomato plants need added fertilisers?

Erik Collado Vidal, an experienced horticulturalist and CEO of Growbarato.net, says: "Tomatoes will grow with only water if the potting mix is initially filled with nutrients. Some bagged mixes are pre-loaded with compost or mineral supplements, and tap water will add trace amounts of calcium and magnesium."

Erik also noted that plants may survive and produce some fruit, but without a steady supply of fresh nutrients, both yield and quality tend to decrease.

Loren Taylor, a seasoned expert in landscaping and gardening, and the owner of Soothing Company, says: "The real secret, though, is in the soil. I have grown tomatoes with nothing but water and no extra fertiliser, and they turned out rich and juicy because the soil was already healthy and full of nutrients."

Loren continued: "When your soil is alive with organic matter, it quietly feeds your plants every day without you having to do much. I make sure my soil has plenty of compost and worm castings mixed in."

This not only nourishes the plants but also helps the soil retain the right amount of moisture while remaining loose enough for roots to grow strong.

How often do they need watering?

David Glass, Bowood's Head Gardener, says: "Keep your plants regularly watered to prevent them from drying out. Use of a weekly tomato feed will help your fruit to ripen. It is also important to cut some of the lower leaves off the stem to allow more light in and increase the air flow around the plant."

Loren Taylor says: "Watering is where a lot of people go wrong. Tomatoes love steady moisture. If the soil dries out too much and then suddenly gets a big soak, the fruit can crack or lose flavour.

"I give them a deep watering regularly so the roots stay evenly moist. Mulch around the base is a simple step that makes a huge difference. It locks in water, keeps the roots cooler, and stops weeds from stealing nutrients."

To conclude, the expert expresses that with the right tomato variety, nutrient-rich, self-sustaining soil, and steady care, you can grow tomatoes that are just as big, juicy, and flavorful as those from a full-sun garden.