Hardy geranium · Peterhof, St.-Petersburg, Russia
When to plant hardy geraniums in Peterhof
Main outdoor window
18 May - 15 Jun
A climate estimate. Check your soil, forecast and cultivar.
Timed from last spring frost
4 May
In Peterhof, on your chosen risk.
First flowers
1 May - 30 Sep
If you plant at the start of the window.
The average last frost. Half of all years are later than this.
Step by step in Peterhof
Download these planting dates (.ics)
Import into Apple Calendar, Google Calendar or Outlook. Dates use the selected risk level and are planning estimates, not frost alerts.
Each window is a planning range. Check the forecast, soil and cultivar before planting; a later date is not automatically safer in hot or wet conditions.
Plant out
18 May - 15 Jun
Two weeks after your last frost.
In flower
1 May - 30 Sep
Hardy geraniums through the year
Against the frost risk in Peterhof
Seasonal context
Rainfall and the growing season in Peterhof
August has the highest average precipitation (90 mm); February has the lowest (38 mm). Compare this pattern with the planting windows and your water supply.
During wetter months, check that beds and containers drain after heavy rain. During drier months, plan how you will keep seeds and new transplants watered. Monthly averages can hide long dry spells and intense storms; they do not show soil moisture, humidity or this week's weather.
Source: NASA POWER, corrected MERRA-2 precipitation, 2001–2020. Values are approximate monthly totals, including the water equivalent of snow, from the nearest 0.5° × 0.625° grid cell. This reference period differs from the temperature record. Rainfall provides context and does not change the calculated planting dates. Method and limitations.
Monthly growing conditions in Peterhof
Compare the planting window with the local temperature pattern. These are historical monthly averages, not this year's forecast or measured soil temperatures. Average frost days do not tell you whether a particular night will freeze.
| Month | Average low | Average high | Frost days |
|---|---|---|---|
| January | -10.4°C (13.4°F)13.4°F (-10.4°C) | -5.6°C (21.9°F)21.9°F (-5.6°C) | 29.9 |
| February | -10.2°C (13.6°F)13.6°F (-10.2°C) | -4.8°C (23.3°F)23.3°F (-4.8°C) | 27.5 |
| March | -6°C (21.1°F)21.1°F (-6°C) | -0.3°C (31.5°F)31.5°F (-0.3°C) | 29.3 |
| April | -0.2°C (31.6°F)31.6°F (-0.2°C) | 7.3°C (45.1°F)45.1°F (7.3°C) | 16.4 |
| May | 5.5°C (41.8°F)41.8°F (5.5°C) | 13.9°C (57°F)57°F (13.9°C) | 2.0 |
| June | 11°C (51.7°F)51.7°F (11°C) | 18.6°C (65.5°F)65.5°F (18.6°C) | 0.0 |
| July | 14°C (57.3°F)57.3°F (14°C) | 21.3°C (70.4°F)70.4°F (21.3°C) | 0.0 |
| August | 13°C (55.3°F)55.3°F (13°C) | 20.1°C (68.3°F)68.3°F (20.1°C) | 0.0 |
| September | 8.5°C (47.3°F)47.3°F (8.5°C) | 15°C (58.9°F)58.9°F (15°C) | 0.0 |
| October | 3°C (37.4°F)37.4°F (3°C) | 7.5°C (45.5°F)45.5°F (7.5°C) | 7.2 |
| November | -2.6°C (27.4°F)27.4°F (-2.6°C) | 0.9°C (33.5°F)33.5°F (0.9°C) | 20.1 |
| December | -7.6°C (18.4°F)18.4°F (-7.6°C) | -3.4°C (25.8°F)25.8°F (-3.4°C) | 28.2 |
For hardy geraniums, also check drainage, sunlight and cultivar requirements. See the rainfall context above; humidity, irrigation and local pest pressure are not calculated.
Local growing check
Before choosing hardy geraniums for Peterhof
- August is the wettest month in the rainfall grid, averaging about 90 mm. Check how your own bed drains and plan watering around actual soil moisture; monthly rain totals are not an irrigation schedule.
The temperature and rainfall tables on this page show the underlying climate estimates. How these suitability checks work · Record what happens in your garden.
Before you plant hardy geraniums
Use the calendar to plan ahead, then check the conditions in your own garden.
- Frost tolerance does not make saturated or frozen soil suitable for planting. Wait until the bed can be worked without smearing or compacting it.
- Harden off plants raised indoors: gradually expose them to outdoor light, wind and temperature before their final move into the bed.
- Check mature size, drainage and cultivar suitability before choosing a permanent position. A suitable planting window does not guarantee long-term survival or fruiting.
Choose a hardy cranesbill and manage its spreading mound
Use a suitable sunny or partly shaded site with drained soil and moisture during establishment. Leave space around smaller neighbours instead of filling gaps based only on the size of the nursery pot.
Monitor seedlings as well as the spreading clump; this geranium can seed freely. Divide rhizomes when renewing a planting and cut back tired growth at the end of the season. Keep the cultivar label with your notes, since seedlings need not repeat a named parent.
What to record this season
Did the mound cover the intended space without overwhelming nearby plants? Add the cultivar, sowing date and conditions to your growing record so you can compare next season.
Further reading: Geranium × oxonianum | Oxford cranesbill . General crop guidance; local dates on this site are calculated separately. Source checked 19 September 2026 by Safe to Plant; this is not an expert review.
The RHS reference is written for UK growing conditions. Use its cultivation advice with local seasonal guidance; UK sowing months are not worldwide planting dates.
How the dates are calculated and their limits · Keep a growing record · Report a local discrepancy
Why these dates
Use a suitable sunny or partly shaded site with drained soil and moisture during establishment. Leave space around smaller neighbours instead of filling gaps based only on the size of the nursery pot.
Check the named variety and local forecast before exposing young growth. The catalog cold-damage figure is a reference, not a guarantee: plant age, acclimatisation, wind and the duration of a freeze affect damage.
This calendar uses frost-relative offsets as a starting point. Hardy geraniums are timed with planting out 2 weeks after it, and this page simply resolves those offsets against the frost date computed for Peterhof.
Peterhof is zone 5b, within the crop's general range. This is an initial cold-hardiness check; cultivar, exposure, drainage and unusual winters can still change the outcome.
The general establishment guide is around year 1, under suitable conditions. This is not a prediction for this location; cultivar, winter conditions and care determine whether it flowers reliably.
Nearby
Hardy geraniums in places close by
Also in Peterhof
Other flowers to time
Growing hardy geraniums in Peterhof
Can I grow hardy geraniums in Peterhof?
The calendar estimates a planting window, not a guarantee of success. August is the wettest month in the rainfall grid, averaging about 90 mm. Check how your own bed drains and plan watering around actual soil moisture; monthly rain totals are not an irrigation schedule.
When should I plant hardy geraniums in Peterhof?
Aim for 18 May - 15 Jun in an average year. If you would rather not gamble on the weather, wait until 29 May - 26 Jun - by then frost has finished in nine years out of ten.
When might hardy geraniums flower in Peterhof?
The estimated period is 1 May - 30 Sep, based on 100 to 130 days from the modeled planting date. Cultivar, planting material and growing conditions can change this interval; check the plant as well as the calendar.
How much frost will hardy geraniums tolerate?
Check the named variety and local forecast before exposing young growth. The catalog cold-damage figure is a reference, not a guarantee: plant age, acclimatisation, wind and the duration of a freeze affect damage.