What to sow and plant in the vegetable garden in April?

By region

Tomato planting, May–June in the north and April–May in the centre, is from Valle d'Aosta and Umbria's calendar; the 16 °C is from the RHS. Potatoes by 20 April are from the Valle d'Aosta Informatore, the window through to 30 June is from Colfiorito, Campania's main crop runs from late March to early May, and Sicily stays on October–November and August–September. French beans from April, at 10–12 °C, are from ARPA Umbria's sheet; poor germination below about 16 °C is from Cornell, and the late-April pot in a cool climate is from the RHS. The April–May onion transplant is from Valle d'Aosta. Broad beans through early May are from the RHS. Spring strawberries, and covering the flowers, are from the RHS. If the packet gives another window, the packet wins. March is in the March calendar, May in the May calendar, and the wider picture in the planting calendar.

Tomatoes and potatoes

In April, in the centre and south, tomatoes go out if temperatures stay above 16 °C, after a couple of weeks of hardening off. In the north, pot them on and wait until May. A cold night stops the planting even after a mild day. Peppers and aubergines have no separate field date on these calendars: keep them to the tomato threshold, and do not push them out into the cold. The months are in when to plant tomatoes.

On the valley floor, early potato planting closes on 20 April, so the tubers form in May and June, as Valle d'Aosta writes it. Higher up, cover if frost is forecast, or wait. In Umbria, April sits inside the window. In Campania it is the main crop. Sicily stays on its other windows. Seed and earthing up are in when to plant potatoes.

French beans, broad beans and onions

In Umbria, sow French beans from April, once the soil reaches 10–12 °C, through to the end of July. If the soil is below about 16 °C, germination is poor: wait, even though the calendar has opened. In the north, open ground is usually late spring or early summer. In a pot the RHS sows from late April in a cool climate, one seed, and moves the plant once frost has passed without breaking the root ball. In the south, start earlier only once frost has passed and the soil is warm. Spacing and depth are in when to plant French beans.

Broad beans can still be sown: the RHS closes in early May. See peas and broad beans. Peas in Campania closed in March. Elsewhere, the 10 °C soil threshold and the packet decide.

Onions are transplanted, in Valle d'Aosta, from April to May. Direct sowing is not: that is May, and only in the lower valley. Umbria has no written April date for the open ground; transplant in spring from the March seedlings, on soil that drains. The windows are in when to plant onions.

Strawberries and basil

Plant strawberries in spring, once the ground is neither frozen nor sodden. Cold-stored runners go in as soon as they arrive, from spring to early summer. If a plant is already in flower and frost is coming, cover it at night and uncover it by day: a frosted flower sets no fruit. Setting the crown level with the soil is in when to plant strawberries.

Basil is still sown indoors, from March to July, at about 20 °C. Outdoors only once frost has passed, nights stay above 10 °C (the RHS threshold) and the soil for heat-loving crops is about 18 °C, the University of Minnesota figure. In April, in the north, plant outside only if those thresholds are already met. The page is when to plant basil.

Jobs for the month

Before planting out, a couple of weeks outside by day, in shelter, and indoors at night. Hardening off does not make a tomato hardy: if it freezes, it stays in. The method is in starting seeds indoors. Water the soil, in the morning, not the leaves: that is the watering guide. A cover on soil that is already warm holds water, as in mulching. In a pot, on a balcony, the compost dries sooner: see the container garden.