Why bother with sweet peas?
Because nothing else smells like that. Vanilla, honey, a bit of orange peel, and a top note of "I have my life together." Sweet peas are the ultimate spring flex for people who plan ahead, which is why we sow them in the depths of winter while everyone else is doom-scrolling seed catalogues.
If you've been waiting for permission to start, here it is. Get your sweet peas in now and you'll be cutting armfuls by October.
When to sow sweet peas in New Zealand
In Auckland, June and July are perfect. Anywhere milder, sow now. Anywhere colder (lower South Island, central plateau), give them an autumn sowing or start in late winter under cover.
Sweet peas are tougher than they look. A bit of frost won't kill them, but a sopping cold puddle will. Drainage matters more than warmth.
The soaking debate
Half the gardening world soaks sweet pea seeds overnight. The other half scoffs. We sit somewhere in the middle. If your seed coats look hard and dark, give them 12 hours in tepid water. If they're plumper, paler, fresher (this year's seed from a decent supplier), just plant them dry. Soggy seeds rot if you forget about them, so set a timer.
Sowing the seeds
Sweet peas have long roots. They want depth, not surface area. Use root trainers, toilet rolls stood on end in a tray, or a deep pot with two seeds per cell.
- Use a free-draining seed mix, not garden soil
- Push the seed 2cm deep
- Water once, then leave the lid off so they don't go mouldy
- Keep in a sheltered, bright spot, not a hot windowsill
Germination takes 10 to 14 days. Don't fuss.
Pinching out (the bit everyone skips)
This is where you become a sweet pea person instead of a sweet pea hoper. When your seedlings have three or four sets of leaves, pinch out the growing tip. Yes, the bit that looks healthy. Yes, with your nails.
Pinching forces the plant to throw multiple side shoots from the base, which means more stems, more flowers, longer vines. Skip it and you'll get one weedy stem and a vague sense of disappointment.
Planting out and support
When seedlings are 10 to 15cm tall and the worst of the wet has passed, get them into the ground. Sweet peas are hungry. Dig in well-rotted compost or sheep pellets before planting.
Set up your supports before you plant, not after. Bamboo wigwams, a teepee of manuka stakes, an obelisk, pea netting against a fence, all good. They climb by tendril, so anything they can grip works. Plant 15cm apart.
Feeding, watering, deadheading
Sweet peas are needy in the best way. Once they're climbing:
- Water deeply once or twice a week. Soggy is bad, dry is worse.
- Liquid feed fortnightly. Seaweed, fish emulsion, or a tomato food works.
- Mulch around the base to keep roots cool.
- Pick. Constantly. The more you cut, the more they flower. Stop picking and they go to seed and quit on you.
The varieties worth your time
Old-fashioned grandifloras smell incredible but have shorter stems. Modern Spencer varieties have longer stems and frillier flowers, slightly less perfume. If you can only pick one, go heritage. The scent is the entire point.
Try 'Matucana' (deep purple, ancient, ridiculous perfume), 'Cupani', or 'King Edward VII' for proper smell. For cutting bunches, 'Mrs Collier' (cream) and any of the Spencers do the heavy lifting.
The honest bit
Sweet peas reward people who keep showing up. Sow now, pinch out, support well, pick often. Do all four and you'll have a vase full of October mornings before anyone else's tulips have made up their mind.
Welcome to the dirt cult. You'll never be normal about flowers again.
