Southern Finnish winter lasts often from December to end of February, but can vary greatly between different years. Spring comes usually in March, and snow melts completely before end of April. Nights will be cold, however, in April and May, with night frosts occurring sometimes even in early June. Therefore plants and seedlings should be covered using gauze to veil them. Usually the gauze can be removed in June, but weather forecasts should be followed to avoid frost damage.

Few tips how to get started in spring:

1. Calcify soil after it has thawed and dried a little, early May being usually a good time. Ideal soil has pH 6 or 7 at most, kits to test soil pH can be bough from some gardening shops. If you’re gardening for multiple years, this does not need to be done every year, and can also be done in the autumn. It is also good to have 1-2 weeks between calcification and fertilization of the soil.
2. Fertilize the soil. Chicken manure is the most common way, compost also works.
3. If the soil is too hard, mix some sand to it. Hard soil can be an issue for vegetables such as carrots or beetroots.
4. The ground should be ready in May-June for planting seedlings and sowing seeds. Check plant information for suggested planting times for some common plants.

Throughout summer and late into autumn the vegetables and fruits can be collected from the garden. It is good to fertilize the plants with fertilizers that contain nitrogen while the plants are growing their leaves. But in July latest it may be good to switch to fertilizers with less nitrogen to help the vegetables and fruits grow faster. Tomatoes for example only need nitrogen until the end of June.

Harvest typically starts in August and continues until the first snow. Some plants like brussels sprouts become sweeter when they get the taste of first snow. Before the first snow however, it is good to plant in November (typically) some flower bulbs, garlic and carrots. This speeds up their growth the next year and carrots for example can be harvested earlier. Also, you can get the first flowers sooner in March and April to decorate your garden. 

The calcification and adding fertilizer is also recommended in autumn. However, calcification shouldn’t be done every year. Measure pH value of the soil before doing it. The autumn fertilizers are recommended.

You can check a summary of the above and some additional info from the following slideset: