Starting with pumpkins – Part 1

Get the basics right for pumpkin production: start with a soil analysis, and then use cattle and poultry manure, says Bill Kerr.

Starting with pumpkins – Part 1
If you start off correctly, it’s easy to grow good pumpkins. Photo: Bill Kerr

New small-scale farmers seldom test the soil before planting, so are ignorant of its fertility or lack of it.

Some feel that because their farming operations are so small, it’s not worth testing the soil. But any new farmer planting more than a very small area – whether to pumpkins or any other crop – should have the soil analysed and consult a fertiliser company on the correct amount and balance of nutrients needed for a good crop.

Even without doing a soil analysis, you can get reasonable results by using manure. To some extent, manure overcomes the imbalance in soil nutrients, as the plants utilise minerals in the organic material.

The latter is the decomposed remains of plants, also called humus.

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The higher the percentage of it in the soil – the so-called organic content – the less fertiliser is needed to grow healthy crops.

Sufficient for all needs
Cattle manure forms the backbone of this approach. Its high organic content helps retain water and promotes rain penetration into the soil. It contains major and minor plant-available nutrients, and stimulates beneficial soil microbe activity.

It also contains a fair amount of nitrogen, promoting plant vigour and healthy green leaves. But unless applied in large quantities, it usually contains insufficient nitrogen to supply all the needs of the crop.

The nitrogen in manure becomes available to the crop over a long period, which may not suit the farmer. So a LAN side-dressing, when necessary, will promote colour leaf and vigour.

Cattle manure usually has a high potassium content, normally sufficient for the crop. However, phosphorous is usually deficient in cattle manure, and most soil in South Africa is also low in phosphorous.

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It is therefore a good idea to add poultry manure, which contains a high level of phosphorous.

Cattle and poultry manure together can often supply all the required nutrients, making it unnecessary to even apply LAN.

Minimum cost and effort
The entire area can be fertilised to avoid patchy growth in the crop. However, for strip cultivation, apply the manure in strips 3m to 5m apart, depending on the crop and variety’s growth type.

Don’t till the soil between the strips; let it remain as veld grass. This will allow you to start with minimum cost and effort. Apply 3kg/m² to 5kg/m² cattle manure
and 1kg/m² poultry manure.

South African soil is normally low in calcium with a low pH unless it has been previously fertilised. If you don’t conduct a soil analysis, and are not in a dry area where the calcium level is sufficient, dig calcific lime into the soil at 300g/m².

Why organic is important

Organic content makes crop production easier and stimulates the soil organisms to extract nutrients that would otherwise have been unavailable to the plants from the soil.

Increase the organic content by applying manure or compost and digging the soil as little as possible – only as much as is necessary to plant. This is the natural way.


Pumpkin facts
Pumpkins are summer-growing annual squashes of several species of the genus Cucurbita. Winter squash is harvested and eaten when the fruit is mature and the skin has hardened.

Pumpkin seeds are a good source of protein, magnesium, copper and zinc.