What to sow, plant and pick this month

An almanac is a book of the year, and this one keeps a single question in front of you: what is worth doing in the garden in the month you are actually standing in. Three ledgers answer it. Sow now is seed going into compost or into the ground. Plant out now is everything that arrives as an object rather than a packet, which means bulbs, tubers, crowns, canes and bare root trees and shrubs. Harvest now is what is ready to pick. An entry can appear in two of them at once, because an onion is genuinely grown from seed by some people and from sets by others, and pretending otherwise would send someone to the wrong shelf.

The compass rose at the top is the whole point of the page. Almost every planting calendar on the internet is written for one hemisphere and then either ignores the other or, worse, adds six months and calls it done. Turn the rose and every list on this page changes to figures that were looked up separately. Your choice is remembered in the same place your plant list lives, on this device, so the log and the almanac agree with each other.

Northern months come from the Royal Horticultural Society, read entry by entry rather than from one calendar, because the reason behind a window matters more than the window. Hardy annuals sown in September and October flower earlier and larger than the same seed sown in spring. Trees and shrubs go in best between October and April, and bare root stock is only sold from about November to March, which is why the winter lists here are full of things you plant rather than things you sow. Tulips are planted late in the autumn on purpose, because cold soil holds back the fungus that causes tulip fire.

Southern months come from South African month by month guides and, for the indigenous plants, from SANBI's own pages. Two of those gave a mechanism rather than a date, which is better than a date: protea seed is sown from the middle of March because germination depends on the swing between warm days and cold nights, and agapanthus is lifted and divided just after it finishes flowering in early March. The southern winter turned out to be the part most calendars get wrong. June and July are not a dead season at all. Lilies go in the moment you buy them, daffodils and tulips are planted, hardy perennials are put in so the roots establish while the top is asleep, evergreens are transplanted, and the deciduous fruit trees and the roses arrive in the nurseries. July is the traditional month to prune, plant and move anything deciduous.

Every figure is stored on the plant's own entry rather than in a separate table, so if you disagree with one you can see exactly which plant it belongs to. The months are for a temperate climate: the north figures suit the United Kingdom and the cooler parts of the United States, the south figures suit Gauteng, the Western Cape coast, southern Australia and the north of New Zealand. Where a region has its own figures, the zone picker above uses them; everywhere else falls back to the hemisphere.

Frost dates, the rainfall season and a month by month guide for each zone are on the region pages, which cover four South African regions, five Australian and three in New Zealand.

Some seed is not sown in a month at all. It is sown a set number of weeks before the last frost, and that date moves by weeks between two towns an hour apart. Where an entry carries that interval, putting your own last frost date into the calendar counts back and places each start date on its day. If you do not know your last frost date, your neighbours will, and a local nursery will know it better than any national average.

Everything here is a starting point rather than an instruction. A late cold spring pushes the whole thing back by a fortnight and no calendar can tell you that. The soil can. Use the month as the reminder to go and look.