GreenlyJohannesburg: frost dates
South Africa
In Johannesburg the last spring frost usually comes around 4 August and the first autumn frost around 5 June, which leaves about 305 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground around 21 August.
| Last spring frost | around 4 August |
|---|---|
| First autumn frost | around 5 June |
| Frost-free days | 305 days |
Median of 2016–2025 for the 25 km grid cell of the city: the last day at or below 0 °C in spring and the first in autumn (ERA5 reanalysis via Open-Meteo). In a cold year a frost can come a week or two later — Greenly warns 48 hours ahead.
When to sow and plant
| Crop | Sow for seedlings | Plant out in a greenhouse | Open ground |
|---|---|---|---|
| Achocha | 11 June | 21 July | 11 August |
| Arugula | — | 23 June | sow 14 July |
| Basil | 9 July | 16 August | 6 September |
| Beet | — | 23 June | sow 14 July |
| Bell Pepper | 3 June | 16 August | 6 September |
| Black-eyed Susan | 10 June | — | 11 August |
| Bok Choy | 16 June | 21 July | 11 August |
| Broad bean | — | 23 June | sow 14 July |
| Broccoli | — | 23 June | sow 14 July |
| Brussels Sprouts | 9 May | 23 June | 14 July |
| Cabbage | — | 23 June | sow 14 July |
| Calendula | — | 23 June | sow 14 July |
| Carrot | — | — | sow 14 July |
| Cauliflower | 12 May | 23 June | 14 July |
| Celeriac | 5 May | 21 July | 11 August |
| Celery | 5 May | 21 July | 11 August |
| Celosia | 19 June | 3 August | 24 August |
| Chamomile | — | 23 June | sow 14 July |
| Chayote | 24 April | 21 July | 11 August |
| Chickpea | — | — | sow 14 July |
| Chili Pepper | 11 June | 24 August | 14 September |
| China aster | 25 June | 16 August | 6 September |
| Chives | — | — | sow 14 July |
| Cilantro | — | 23 June | sow 14 July |
| Corn | — | 21 July | sow 11 August |
| Cosmos | 19 June | 3 August | 24 August |
| Cucumber | 5 July | 16 August | 6 September |
| Daikon | — | 23 June | sow 14 July |
| Delphinium | 16 May | — | 14 July |
| Dill | — | 23 June | sow 14 July |
| Eggplant | 7 June | 16 August | 6 September |
| Florence fennel | 6 June | 21 July | 11 August |
| Garden sorrel | — | 23 June | sow 14 July |
| Green Beans | 14 June | 21 July | 11 August |
| Hyssop | — | — | sow 14 July |
| Kale | — | 23 June | sow 14 July |
| Kiwano | 29 June | 31 July | 21 August |
| Kohlrabi | — | 23 June | sow 14 July |
| Leek | 14 April | 23 June | 14 July |
| Lemon balm | — | 23 June | sow 14 July |
| Lettuce | — | 23 June | sow 14 July |
| Lisianthus | 28 March | 23 June | 14 July |
| Lovage | — | — | sow 14 July |
| Luffa | 5 July | 16 August | 6 September |
| Marigold | 9 June | 21 July | 11 August |
| Melon | 25 June | 16 August | 6 September |
| Microgreens | — | 3 August | sow 24 August |
| Moringa | 30 June | 24 August | 14 September |
| Mustard greens | — | 23 June | sow 14 July |
| Napa cabbage | 18 June | 21 July | 11 August |
| Nasturtium | 13 June | 21 July | 11 August |
| Okra | 5 July | 16 August | 6 September |
| Oregano | 24 April | 23 June | 14 July |
| Pansy | 28 April | 23 June | 14 July |
| Parsley | — | 23 June | sow 14 July |
| Parsnip | — | — | sow 14 July |
| Peanut | 10 July | 16 August | 6 September |
| Peas | — | 23 June | sow 14 July |
| Petunia | 14 June | 16 August | 6 September |
| Physalis | 16 June | 31 July | 21 August |
| Pumpkin | 24 June | 31 July | 21 August |
| Purple coneflower | 13 May | — | 14 July |
| Radish | — | — | sow 14 July |
| Sage | 5 May | 23 June | 14 July |
| Snapdragon | 19 April | 23 June | 14 July |
| Spinach | — | 23 June | sow 14 July |
| Stevia | 12 June | 31 July | 21 August |
| Stock | — | 23 June | sow 14 July |
| Sunflower | — | 3 August | sow 24 August |
| Sweet Corn | — | 21 July | sow 11 August |
| Sweet pea | 12 May | 23 June | 14 July |
| Sweet William | — | — | sow 14 July |
| Swiss Chard | — | 23 June | sow 14 July |
| Thyme | — | 23 June | sow 14 July |
| Tomato | 4 June | 31 July | 21 August |
| Turnip | — | 23 June | sow 14 July |
| Watercress | — | 23 June | sow 14 July |
| Watermelon | 15 July | 16 August | 6 September |
| Zinnia | 20 July | 24 August | 14 September |
| Zucchini | 29 June | 31 July | 21 August |
Planting out: a week after the last frost once the soil is warm enough for the crop; frost-hardy crops three weeks before it; an unheated greenhouse three weeks earlier. Seedlings are sown so they are ready on that day.
Johannesburg: weather for the next 7 days
Forecast by Open-Meteo. Nights at or below 0 °C are marked as frost.
Planted in autumn
| Crop | Plant around |
|---|---|
| Bearded Iris | 6 May |
| Crocus | 6 May |
| Daffodil | 6 May |
| Garlic | 6 May |
| Hyacinth | 6 May |
| Lily | 6 May |
| Peony | 6 May |
| Saffron | 6 May |
| Tulip | 6 May |
| Wild garlic | 6 May |
A month before the first autumn frost, so the roots grow before winter.