Seasonal Planting Schedule for Bohemia and Moravia

Climate Baseline for Scheduling

The schedule below references climate normals from the ČHMÚ 1991–2020 dataset. Average last frost dates for representative Czech stations: Praha-Ruzyně — 11 April; Brno-Tuřany — 8 April; Olomouc — 15 April; České Budějovice — 25 April; Liberec — 3 May; Šumperk — 10 May. Gardeners working above 500 m elevation should add approximately 7–10 days to each date.

First autumn frost dates follow a similar geographic gradient: Praha lowlands — around 19 October; Moravian uplands — mid-October; elevated Bohemian basins — late September. These dates govern when tender plants must be lifted or protected.

January — Dormancy and Planning

January temperatures across Czech lowlands average −2 to −4 °C with minima reaching −12 to −18 °C during cold spells. Ground is typically frozen to 20–40 cm depth. This period is unsuitable for outdoor soil work but allows useful preparatory tasks.

• Order seeds and bare-root stock from Czech suppliers (Semo, Floraservis, Sempra) in advance of spring shortages.
• Check stored dahlia tubers, gladiolus corms, and begonia tubers for rot. Affected sections should be removed and cut surfaces dusted with sulphur powder.
• Prune deciduous fruit trees (jabloně, hrušně) during mild spells above −5 °C. Avoid pruning during deep frost when wood is brittle.
• Apply winter wash (Dormant Oil / olej) to fruit trees against overwintering scale insects and aphid eggs if not done in December.

February — Early Preparations

Late February often brings the first mild spells (above 5 °C daytime) in the Praha and Brno lowlands, though reliable warming requires confirmation from local forecasts rather than calendar dates alone.

• Sow chillies (Capsicum annuum) and early aubergines under heated glass or on a south-facing windowsill at 20–24 °C. Germination requires 10–21 days at these temperatures.
• Start onion sets (cibule sazečky) under cool glass (8–12 °C) for early transplanting.
• Clear fallen leaves from lawn areas — extended wet leaf cover promotes the fungal conditions conducive to Microdochium snow mould, which becomes visible as snow recedes.
• In protected cold frames or unheated polytunnels: sow broad beans (Vicia faba) for early spring transplanting.

March — First Outdoor Sowings

Soil temperatures at 10 cm depth reach 5–7 °C across Czech lowlands by mid-March in typical years. This is the minimum threshold for most cool-season vegetable germination. Beds should be prepared only when soil is friable — the squeeze-and-crumble test (soil forms a ball but breaks apart easily) confirms workability.

• Direct sow: spinach (Spinacia oleracea), radishes (Raphanus sativus), lettuce (Lactuca sativa hardy varieties), peas (Pisum sativum).
• Under glass or indoor trays: tomatoes, sweet peppers, celery, leeks.
• Plant bare-root deciduous shrubs and trees: roses, currants, gooseberries. These establish better than containerised stock planted later in the season.
• Divide established perennial clumps (echinacea, phlox, geranium) before new growth reaches 5 cm.

April — Post-Frost Planting Window

The practical post-frost window for most Czech lowland stations opens in mid-April, though cold snaps occur through late April — the Czech gardening expression „Studení muži" (Cold Men saints' days, 12–14 May) marks the traditional last frost risk period. This folk reference has reasonable statistical support: ČHMÚ data shows that overnight temperatures below 0 °C occur after May 15 in fewer than 5% of years across the Praha and Brno lowlands.

• Transplant cold-tolerant seedlings: brassicas (cabbage, broccoli, cauliflower), lettuces.
• Plant out hardened-off sweet peas (Lathyrus odoratus) against supports.
• Apply the season's first organic mulch to permanent beds — compost or bark at 5 cm after soil has warmed somewhat.
• Begin lawn feeding programme. Czech agronomists recommend nitrogen-dominant spring fertiliser (e.g. 20:5:10 N:P:K) at 20–30 g/m² in April.

May — Full Planting Season Opens

After the Cold Men (mid-May), tender summer plants can be transplanted outdoors across all Czech lowland regions without frost protection. This is the busiest single month in the Czech garden calendar.

• Transplant tomatoes, courgettes (Cucurbita pepo), cucumbers, and basil outdoors after 15 May.
• Plant dahlia tubers in their permanent positions (minimum soil temperature 10 °C at planting depth).
• Direct sow French beans (Phaseolus vulgaris), runner beans, sweetcorn.
• Stake tall perennials (delphiniums, peonies) before flower stems reach 40 cm to avoid wind damage.

June to August — Growing Season Management

Summer maintenance in Czech gardens centres on irrigation management during dry spells, pest monitoring, and succession sowing of fast-maturing crops.

• Irrigation: drip lines or morning hand watering is preferred over evening overhead irrigation, which increases fungal disease pressure on tomatoes and roses. Target 20–25 mm per week at soil level during dry periods.
• Deadhead flowering perennials (echinacea, nepeta, salvia) to extend the flowering period into September.
• Monitor for box tree moth (Cydalima perspectalis) if any Buxus remains — this pest completes 2–3 generations per Czech summer season.
• Succession sow lettuce, dill, and radishes every 3 weeks through July for continuous harvest.
• Collect seed from self-seeding annuals (calendula, nigella, borage) for the following season.

September and October — Autumn Planting

Autumn planting of spring-flowering bulbs and hardy perennials is the highest-leverage activity in the Czech garden year. Soil temperatures remain above 10 °C until late October across lowlands, allowing root establishment before winter dormancy.

• Plant tulip bulbs from mid-October to November at 15 cm depth. Earlier planting risks botrytis infection if soil temperatures are still high.
• Plant narcissus and allium bulbs from September onwards — these benefit from earlier planting than tulips.
• Transplant and divide established perennials: this window is often overlooked but produces faster establishment than spring planting on warm Czech loam.
• Lift dahlia tubers after the first frost kills the foliage. Cut stems to 10 cm, dry for 48 hours, and store in frost-free conditions (3–7 °C) in barely moist vermiculite or wood shavings.
• Sow overwintering garlic (Allium sativum) October–November for June harvest the following year.

November to December — Closing the Season

• Apply winter mulch around borderline-hardy perennials after the first significant frost has hardened the plants. Mulching too early on unfrosted soil can encourage continued growth that is then frost-damaged.
• Prune roses to approximately 40 cm, mound soil around the graft union for protection, and wrap climbers loosely with hessian in exposed positions.
• Complete bare-root planting of deciduous trees and shrubs by late November while ground is workable.
• Service garden tools: sharpen blades, oil wooden handles, clean and store sprayers. Frost damage to residual moisture in sprayer mechanisms is a common cause of failure the following spring.

Data Sources

Frost date statistics referenced from ČHMÚ climate normals 1991–2020. Planting timing guidance cross-referenced with the Czech garden calendar published annually by Zahradkari.cz.