Why is it harder to garden in winter?
There are three factors that wreak havoc with the gardens in Joburg in:
1. In winter there are about 3 hours less of sunlight per day than in summer
2. The differences in temperatures are also quite extreme, where we see average lows of 7 deg in winter verses and average high of 32 in Summer.
3. And then moisture, we see on average 0.1 mm or rain in the winter months versus a maximum average of 185 mm in the summer
This means we have cold, dry and relatively dark winter days. And it affects the plants and also the soil
Slower growth in plants is caused by
Number of hours reduced photosynthesis
Temperature of water content in plants drops so they spend more time in the day regulating internal temperature, getting up to a normal functional levels
This effect on plants can also cause the water in plant molecules to freeze which is when we see frost.
Soil is affected by the above mentioned factors because the microorganisms are mostly dormant in the colder temperature, again as a result of a lower amount of solar energy as well as minimised soil temperature.
The lower water flow and availability of nutrients in the soil results in slower production of plant growth and plant recovery
Also, it’s cold and mis, and we’d rather be inside so the garden suffers because its guardian would rather be drinking hot chocolate by the fire

So all in all, it’s recipe for a sad picture, isnt’ it?
But it’s not all bad news! Winter can bring some great opportunities for your garden.
Some plants need winter cold. Winter plants require a process called vernilisation to flower and produce seeds and fruit. Pest control is at a big advantage in winter as pest populations drop off largely due to cold and dry soil, also fewer soft tissue plants to prey on. Some plants are completely dormant during winter which makes it a great time to move and relocate where required. So if you have any that need to move, June/July would be the time.
So now that we know what the factors are, what do we do? Firstly, if you aren’t doing it already, develop a strategy to work towards winter.
From Jan – March, What I’m doing in the garden:
- Focusing on my basil and making boat loads of pesto to freeze for winter dishes
- Focusing on my green beans as they are great as a frozen veg
- Trying to get at least two harvests from my pumpkins for use in winter
From March – May Focus on sowing: brassicas leafy veg root veg and peas
Now I have a pantry supply of garden produce and an already half way mature stock of leafy greens for early winter.
Then, for May and June I'm staking the Autumn peas, which are now flowering Harvesting radishes and leafy greens.
Winter Planting
Seeds: radish, lettuce, baby spinach, more peas (for second harvest), root veg such as beetroot or celeriac and parsnip, onions and shallot, and herbs such as coriander
Seedlings: Spring annuals, artichokes (for larger plants in October), kale, lettuce, lambs lettuce, herbs such as parsley, dill and winter thyme, sage, brassicas such as cauliflower, broccoli, savoy cabbage
By planting a combination of seeds and seedlings continuously you spread out the harvest period.
For Spring annuals: Choose a site that will be the most showy in early spring Prepare soil by turning over once and fertilising with 3:1:5 Mulch with bark chip or straw Plant poppies, sweet peas, echinacea, foxgloves etc
Feeding the soil
Winter is a very good time to build the soil for spring. But it’s done differently than in spring. Instead of compost, use a fertiliser
3:1:5 for fruit and flower
6:3:4 for veggies
Nitrogen – growth of leaves, phosphorous, - root, flowers and fruit
potassium – overall function
Or, Margaret Roberts Supercharger every 2 weeks sprayed on leaves late morning on warmer days
Before deciding on gardening activity, check the 10 day forecast for temps, and rain
Mulch
Around seedlings that you’ve planted or in spaces around shrubs
In beds that you won’t do anything with during winter focusing on the areas that are most visible to you and you want to perform well in spring.
The power of mulching cannot be over emphasised. As you remember, soil is one half of the plant growth equation. If you have planted your winter varieties, you can get much better growth by ensuring water and nutrients are available to them. The best way to do this is to keep a blanket on the soil and help keep soil temperatures consistent.
Watering
Play it by ear and keep an eye on the weather report.
You would be better off watering late morning than any other time of day. Only water when the temp is above 10 deg, preferably more than.
Longer, less frequent watering sessions are better than shorter more frequent.
Pests
Soil – turn or double dig areas that have shown signs of pest populations, especially if you are not plating there. Simply expose the under layer of the soil to the top.
Leaves and fruit (lemons): spray Oleum on plants with pest issues, following the instructions for repeat application. Oleum is not strictly organic but it has a very low toxicity while being highly effective
You can also use Ludwig’s organic insecticide, which is effective but requires more repeat application
Birds
Birds can be a blessing in disguise or an absolute menace. I believe in bird management rather than bird control, as I have lost the game time and time again.
I cover my soft leaf veg with shade cloth to protect from mouse birds and Loeries . This would be spinach, cabbage, broccoli, cauliflower
I make use of bird life increase and diversion tactics. I have a bird feeder near the veg garden, within site of the lounge window, here I place bird seeds and fruit every day. This help draw attention away from the veggies and onto the food. In winter we et some of the most amazing sightings as food source is low for the birds.
I hope these tips can assist you in facing the threats of winter on the veggie garden, and good luck!