Tomato

Plant tomatoes outside after the last frost, typically late May to early June in most of the UK. Harden them off for 1–2 weeks first by placing them outside during the day and bringing them in at night.

Tomatoes fruit best under glass in the UK. Outdoor crops work in warm, sheltered spots in a good summer, but greenhouse plants produce earlier, more reliably, and over a longer season.

Yes, tomatoes grow well in pots and are a good choice for patios and balconies. Use at least a 30–40cm diameter pot per plant (bigger for cordon varieties, smaller is fine for compact bush or tumbling types), with a good multi-purpose or John Innes No. 3 compost. Container plants dry out faster than border-grown ones, so check daily in warm weather and feed weekly once flowering starts, since pots hold far less reserve nutrition than open ground. A grow bag can typically support 2–3 plants.

Water consistently: roughly every 1–2 days in warm weather for container plants, every 2–3 days for border-grown. Irregular watering causes blossom end rot and skin splitting. Mulch the base to retain moisture.

Blight (Phytophthora infestans) causes brown patches on leaves and fruit rot, spreading rapidly in warm, humid conditions. Prevent it by watering at the base (not over leaves), removing affected growth immediately, and growing blight-resistant varieties.

For cordon (single-stem) varieties, yes, remove side shoots from the leaf axils to keep energy directed to the main stem and fruit trusses. Bush and tumbling varieties do not need pinching out.

Towards late summer, "stop" cordon plants: cut out the growing tip above the top flower truss you want to keep, and remove any new side shoots up there too. This tells the plant no more new growth is coming, so it redirects its energy into ripening the fruit it already has, rather than starting trusses that will never mature before the cold sets in. For any truss that's clearly not going to ripen in time as nights get colder, cut the whole truss off and hang it somewhere warm and dry indoors, it will keep ripening off the plant. Individual unripe tomatoes can also be ripened in a paper bag with a banana: bananas give off ethylene as they ripen, which speeds up the tomatoes alongside them. Never put tomatoes in the fridge to ripen, the cold stops the ripening process rather than helping it.

Feed tomatoes in two phases. From planting until the first flowers open, use a balanced liquid feed every two weeks to build a strong plant. Once flowers appear, switch to a high-potassium feed (such as a purpose-made tomato feed or comfrey liquid) and continue weekly until the end of the season. Continuing with a balanced or nitrogen-heavy feed after flowering causes lush leafy plants that produce very little fruit.

Yes, ants on plant stems in spring and early summer are almost always a sign that an aphid colony is already present nearby. Ants farm aphids for their sweet honeydew secretions, and actively protect the colony from natural predators like ladybirds and lacewings. If you see ants running up a stem, check the growing tips and the undersides of the youngest leaves immediately. Look for clusters of small soft-bodied insects: black, green or grey depending on the species. Catching the colony early makes a huge difference: remove affected leaves and bin them (do not compost), then check again every two to three days. Do not squash the ants themselves: address the aphids and the ants will leave once their food source is gone. A useful short-term trick: place a piece of watermelon, melon or any sweet fruit near the base of the affected plant. Ants are strongly attracted to the sugar and will move to the easier food source. While they are distracted, spray or remove the aphids from the plant. Once the aphid colony is gone, the ants have no reason to return to that plant.

Possibly yes. High nitrogen levels in plant sap make it significantly more attractive to aphids: the sap becomes richer in amino acids which is exactly what aphids feed on. If you are seeing persistent, heavy aphid infestations despite treatment, check your feeding regime. Fruiting crops like tomatoes that are still being given a nitrogen-rich balanced feed after flowering are especially susceptible. Switch to a high-potassium feed at first flower and reduce overall nitrogen. Healthy, well-balanced plants are more resistant to aphid attack than over-fed ones.