TIPS & PROBLEMS

MY SEEDS DIDN’T COME UP!

Some growers recommend scarifying (scratching the seed surface) before sowing, and others like to soak the seeds in water for a few hours prior to planting to increase germination rates. Sometimes it’s just a question of temperature or moisture levels. The general advice is to sow seeds into moist soil and not water again until the first green shoots poke through. However, if the soil is too dry, seed won’t germinate – likewise, if it’s too warm, cold or wet. Put your finger in the soil to check. If you’re really not sure, follow the step-by-step on the next page, which shows how to sow seeds in trays and plant out when conditions are right.

BEST SOWING TIME

The benchmark used to be St Patrick’s Day, in March, as peas germinate best when soil is cool, that is, below 20˚C. However, autumn often brings hot, dry weather, and trials have shown that sweet pea seeds can be sown as late as winter. In cool zones, a successive spring sowing results in summer flowering.

IS LIME NECESSARY?

Sweet peas prefer a slightly alkaline soil (pH 7–8). If your soil is acidic (pH 6.5 or less), apply liquid lime and dolomite before planting. This no-dig approach works faster than incorporating granular lime or dolomite, as the particles are smaller.

SET UP A SUPPORT

Climbing sweet peas can reach more than 2m high, and need something to climb up. Install supports before sowing seed. A simple tripod or teepee made of stakes or bamboo canes, wound with sturdy garden twine, is adequate. Wire climbing frames can be re-used each season, or buy some timber or plastic lattice.

WHEN TO PICK

Sweet peas are annuals, so their mission is to grow, bloom and set seed. Picking or deadheading regularly encourages more flowers, and delays seed production. If you want to save seed for next year, allow a few to set pods towards the end of the season.

LACK OF FLOWERS

This can be caused by too much shade, compost or high-nitrogen fertiliser. Apply a complete fertiliser, then once buds begin to form, use a fertiliser rich in potassium, sold as ‘flowers and fruit’ fertiliser.

PEAS IN A POT

Choose a large container, at least 40cm in diameter and depth, for taller growers. Dwarf varieties are happy in troughs or patio pots. Fill with quality potting mix.

IN THE SUBTROPICS

Most peas prefer a cool to temperate climate with mild summers – they will struggle in the tropics. In the subtropics, sow seed as soon as the weather cools in mid to late autumn. The flower display will finish once the hot weather arrives in mid spring. Humidity is not a friend of the sweet pea, as powdery mildew may weaken growth. You can treat powdery mildew using an organic fungicide.