What Is The Best Fertilizer For Growing Peas?

By Paul Smart •  Updated: 02/13/21 •  7 min read

What Is The Best Fertilizer For Growing Peas? Peas are one of the easiest plants to grow in your garden. They germinate quickly and easily in most soils and will grow well in most climates in the cooler parts of the growing season, Autumn and Spring. However, to get the maximum out of Pea plants do we need to fertilize, and if so with a type of fertilizer?

The yield generated from a Pea plant does not generally improve significantly with the addition of fertilizer. A study from the University of Dicle assessed a range of fertilizers and found that in most cases there was little or no change in the yield and in some cases the addition of certain types of fertilizer was actually detrimental to the yield.

However, when there is a deficiency in the soil of phosphorus the addition of a phosphate based fertilisers can provide some benefit in yield. But, the addition of Nitrogen based fertilisers will not have any significant affect.

The reason for this is that the Pea plant is a Legume. Legume plants are commonly referred to as “Nitrogen Fixers” because they are able to take nitrogen from the air and make it available in the soil.

In this process, a bacteria, that resides in the nodules of the root systems of the plant, help the plant to take up atmospheric nitrogen and store it in the root system allowing the plant to grow.

When the plant dies the nitrogen stored in the nodules of the plant is released thereby increasing the nitrogen level of the soil helping fertilize the soil for subsequent crops. This strategy, used by some gardeners, is referred to as “Green Manure”. Green Manure is sometimes planted as a cover crop between productive crops. It is allowed to grow to around knee height before being cut down to the ground and dug into the soil.

However, to avoid deficiencies in your soil it is best to add compost on an annual basis. This addition is sufficient to provide all the nutrients required for your crops.

How To Grow Peas

Peas are a very hardy crop that grows well in the cooler parts of the year. Peas are tolerant of frost and will survive relatively low temperatures. Peas are unaffected by temperatures down to 28°F (-2°C) and will survive with some damage down to 20°F (-6°C). However, if protection is provided to the plants Peas can survive temperatures as low as 10°F (-12°C).

This temperature tolerance allows Peas to be planted relatively early in Spring and in regions where the winters are mild the sowing can be commenced in Winter. These mild conditions also enable Autumn plantings to be overwintered allowing a really early Pea crop to be produced.

When planting out Peas it is common to sow directly into the soil however in regions with really cold winters it is advisable to sow Peas seeds indoors because this will accelerate the growth rate. While Peas are highly tolerant of cold temperatures they will still require a temperature around 41°F to 50°F (5°C to 10°C) or higher to grow at a reasonable rate.

Additionally, if un-germinated seeds spend an extended period of time in the soil there is a greater risk of them rotting or eaten by vermin such as mice.

To optimize the germination rate and growth of the seedling it is best to use a heated propagation tray. This is because it is much easier to maintain a constant temperature and a relatively humid environment. If you do not currently own a heated propagation seedling tray the unit we recommend is shown in the image below, we prefer it because it has a vented humidity dome to help control the growing environment as well as a removable seedling tray which can easily be replaced in the future if required. Click here to see the latest price on Amazon.

When it comes time to plant the Pea seeds they should be sown at a depth of 1 inch (2.5 cm). If you are planting them in a modular tray it is advisable to use seed raising mixture rather than garden soil. Place two seeds per cell to ensure that all the cells within the tray are occupied, once planted the seeds should take around 7 days to appear. In a warm controlled environment, Pea seedlings will grow relatively quickly usually requiring only 3 to 4 weeks before they reach a sufficiently large size that will allow them to be planted outside.

When planting them out in the garden the seedling should be spaced approximately 2 to 3 inches (5 to 7 cm) apart. As Peas grow on a vine it is necessary to erect a support structure. This is best put in place at the same time as the seeds are sown the main reason for this is that it will avoid the need to disturb the roots of the plants later.

As the Peas have tendrils that allow them to climb the structure it is best to use a support system such as a wire or plastic trellis as it provides many different points for the plant to cling to the support structure. However, despite the Peas capacity to cling to the structure with its tendrils, this is usually not sufficient to keep the plant upright. It necessary in most cases to tie the Peas to the structure, this is most easily done by wrapping a piece of string horizontally around the surface of the structure at different heights rather than tying the plants individually to the structure.

In terms of soil preparation the method we generally recommend using is the ‘No Dig’ method as it is easy and simple to implement. The method requires a layer of compost to be applied once a year, the best time is in Autumn. The reason for this is that the compost will suppress weeds for several months. When applying the layer it needs to be 2 to 4 inches thick to ensure that the light is excluded from the soil.

The primary benefit of using this method is that it reduces the volume of work required in the garden because the compost acts as a mulch suppressing weeds and retaining moisture. To read more about this method click here. Alternatively, watch the video below from Charles Dowding which explains how the method is applied.

Harvesting Peas

Over time the plant will develop and the established vine will begin to produce flowers. These flowers will produce, initially flat pods, the pod will fatten overtime to the stage where they become slightly thicker than a pencil. This is usually the stage at which pods can start to be harvested however, it worth experimenting a little bit with a pod or two by opening up them to check the size. You will find that you quickly get a feel of pods that should be picked.

Once the Peas begin to crop it is important to pick them every couple of days as this will encourage the plant to continue to produce new flowers and then pods. Pea plants are quite vigorous and will continue to produce as long as the temperatures remain between 50°F to 85°F (10°C to 26°C). At a temperature below 50°F (10°C) the growth rate will slow to the point where the vine stops producing flowers. However, when the temperatures rise above 80°F the Pea plants will begin to die.

Collecting Pea Seeds

Once you have purchased Pea seeds and started to grow them in your garden it is easy to collect seeds year on year, which will ensure you never have to purchase the seeds again.

To collect seeds you simply need to let the plant flower and it will create pods. As the Peas swell and are ready to harvest save a few pods for seed. Allow the pods to dry out on a shelf somewhere before storing them in a paper envelope.

However, it is important to note that it is not actually necessary to remove the pods from the plant, they can simply be left on the plant and removed at the same time as the plant is removed at the end of the season.

Paul Smart