Sweet peas

Sweet peas

Article originally published by: Kiwi Gardener

Singing the praises of sweet peas – tough little bloomers that can light up the garden year-round.

Whenever I’m asked what my favorite flower is, I struggle to answer as I have so many. It’s like asking which is your favourite child – how do you choose? My top picks always include dahlias, gladioli, daphne, and daisies; I am never without roses or hellebores no matter where I live, and every year without fail I grow sweet peas anywhere I can find room to squeeze them in.

I’m not sure where my devotion to them came from – my uncle Teddy used to grow them in French Farm in the 1970s, so it may have been from there, although I have always loved any flower I can pick for a posy, and have a special affection for any bloom that will give someone joy when they’re presented with it.

New Zealand has a strong history with sweet peas, both in terms of seed production for English and European seed catalogues and sweet pea breeding. Dr Keith Hammett is the godfather of sweet pea breeding; he has a passion for these blooms that just captivates you. Keith’s interest in the sweet pea started off as a teenager, when his uncle decided he wanted to separate his flower and vegetable garden, doing so by planting a dividing row of sweet peas. To hear Keith recall it, it was love at first sight. This love has only continued throughout the years, as sweet pea varieties bearing the Hammett name are now sold all over New Zealand and around the world.

I first met Dr Hammett about 20 years ago, and was struck by his contagious keenness for both breeding plants and creating cultivars that fitted the local New Zealand climate. I couldn’t quite keep up with all the different characteristics he was producing and aiming for, but was mesmerised and wanted to soak up what I could, knowing that I could stand to learn a lot from him. So I sat and listened, barely saying a word!

L: Packed with perfume, ‘High Scent’ is a tremendous variety to plant. R: Look at all these blooms! ‘Pink Nines’ is a tremendous variety for the show bench.

Fast forward a few decades and every year I plant out dozens of his varieties. My go-to is his ‘High Scent’ as it has got the most magnificent fragrance, and beautiful flowers with an antique cream base and delicate violet edging on each petal. One of its best features is probably its prolific blooming capacity, as once it starts flowering in November I can be picking it continuously until the end of March, as long as I pick off any spent flower seed pods along the way, and make sure to fertilise and water them regularly. Like me, they love their tucker!

For the show bench I always plant ‘Piggy Sue’ (not to be confused with Peggy Sue), named after a pig rescued from farrowing stalls. Its colouring is a pink flush against a cream ground, with young flowers that often resemble a pink picotee when they first open. ‘Paradox’ has an intense, rich, violet-blue flower but has lost its ability to climb, so is one you would plant as a ground cover or for use in hanging baskets.

Keith says all the sweet peas he offers are great for picking, reminding me that “Sweet peas are the ultimate ‘cut and come again’ flower”, meaning that the more you pick from the flower stems, the more they will produce. This is a total win-win for us at home who can never have too many of these gorgeous blooms.

He goes on to mention that “The ones with the larger, frilly flowers have longer stems than, say, some of the smaller flowered forms with the strongest scent.” His most highly-scented varieties are ‘Original’, ‘High Scent’, ‘More Scent’, and ‘High Society’.

New release ‘Enigma’.

When, Where & How

  • Plenty of sun needs to be on the menu – while sweet peas will bloom in half-day sun, the results are always best when they are planted somewhere that gets rays all day.
  • Sow seeds now or look for seedlings, as they are in the shops throughout August, September and into October.
  • Seeds can be sown directly where they are to flower provided the soil is well drained, in a sunny position, and you are able to protect against slugs, snails and maybe birds.
  • If sown into pots for planting out later, seeds do not need to be grown inside or in the glasshouse, simply sow and place outside in full light. Keith advises to never soak seeds before sowing.
  • Provide support – sweet peas are a tumbling vine and need something to cling to when climbing. This support can be as simple as bamboo canes, wigwams, or old bike wheels, while netting against a fence or wall is an enduringly popular choice. Keith often suggests making a simple tepee by selecting tall bamboo canes or finding some tall slender prunings from apple or plum trees, then poking them into the ground in a circle about 70cm in diameter, tying the tops of the bamboo or branches together and weaving string around the structure so the sweet peas have something for their tendrils to cling onto.
  • Sweet peas need plenty of nutrition to keep blooming and prefer a soil that can lock in plenty of moisture to maintain active growth. As soon as the soil dries out for any period of time, the plant thinks its life is nearing the end and it begins to wilt and prepare to set seed, so avoid this with regular watering. This can present problems with tubs and planters.
  • Mildew or grey mould can be an issue, especially early in the season before the days become longer. It often appears if humid weather allows the plants to dry out, and can be counteracted with a monthly drenching with Seasol, although some recommend spraying with baking soda on a weekly basis instead.

Homemade baking soda spray

A weekly spray of the following mix can slow mould spread and prevent further attack.

  • 1 litre of water
  • 1 tsp baking soda
  • 1 tsp cooking oil
  • 2-3 drops dishwashing liquid

Did you know?

Summer-flowering sweet peas need 12 or more hours of daylight each day before they are able to flower. If sown too soon, plants grow very tall before they come into bloom, and similarly, if they are sown when days are long, they will not flower until they have been through the following winter.

Tougher than they look

As Dr Keith Hammett will tell you, sweet peas may look delicate and feminine, but they are surprisingly tough. These fine flowers will germinate and grow at low temperatures. In northern New Zealand, delay sowing seed until June at the earliest.