Sweet peas are such beautiful looking and smelling plants, and now a days there are so many different varieties, that there really is no reason to let lack of space stop you from growing them.
Photo by teal chick
Recently, Mimi of Israeli Kitchen, asked me this question:
“I’d like to plant some sweet peas in a windowsill – windowsills are all I have. But I’m concerned that they won’t get enough sun. Can you tell me how much sun exposure sweet peas need? I have fantasies of pink and purple flowers climbing up the security bars come springtime…”
Sweet peas generally need full sun to flower profusely, preferably morning sun, because most varieties don’t do too well in hot temperatures. Areas with direct afternoon sun tend to be hotter than those with morning sun. If you don’t think your intended spot gets 6 hours of sunshine, you might try a perennial sweet pea (Lathyrus latifolius) as opposed to an annual sweet pea (Lathyrus odoratus) because the perennial types seem tolerate more shade than the annual kinds. Although, as I mentioned, they won’t flower as much with less than 6 hours of direct sun. Long periods of dappled sunshine or indirect light might be able to make up for the lack of direct sun, depending on how bright the area is.
When growing sweet peas from seed, you need to “scarify” the hard outer coating of the seed. You can do this by rubbing the seed lightly with sand paper or nicking them with a nail clippers. In Mediterranean climates like Southern California or most parts of Israel, you can plant sweet peas as early as right now (late autumn), for mid-winter flowers, or in early spring, for late-spring flowers. Or, if you’re really organized, you can plant some right now and some in spring to extend your bloom time. If you live in a harsher climate, you can start them inside 4-6 weeks before your last frost and then transplant them as soon as your soil thaws or just sow the seed directly outside at that time.
For those small space gardeners who don’t want a vining variety to cover security bars or balcony railings (which the traditional varieties would be happy to do), there are newer types that form nice mounds for hanging baskets or pots, and don’t require a trellis. For example, check out Little Sweetheart or Knee High.
Are you an experienced sweet pea grower? What special tips or tricks do you have to get the most out of your plants? Do you have any recommendations for varieties that will flower without direct sun?
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Here is some helpful information from our website.
Sweet Peas can be a little tricky to germinate, but well worth the effort! They require ‘scarification’ to break their hard seed coat. The easiest method is to presoak them for 8 – 24 hours before planting. Be sure to plant them as soon as possible after the soaking period, or they will begin to rot in the water. Alternatively, you can lightly roll them on a piece of sandpaper, so the coat gets nicked. Then, sow at the recommended depth of 1”.
Sweet Peas need cool temperatures to germinate. They will begin to sprout when temperatures are around 55 to 65 degrees.
Cold winter climates: Sow in very early spring. This means St. Patrick’s Day or as soon as you can work the soil. If you are having a dry spring, keep the area watered (but not soggy), so the seeds remain viable until ready to sprout. Sweet Peas can sometimes take as long as 2-4 weeks to sprout, so be patient. The plants can handle light frosts –don’t worry about planting too soon!
Warm winter climates: Sow in August or early September for mid-winter bloom. If you have a warm fall, it might be better to wait a little later in the season to plant. In warm climates, you may be able to plant as late as January or February.
Planting Outside: It’s best to plant them in a well-drained area. If you have a lot of rain or over water the area, they may rot in the soil and not come up. The seedlings are coveted by birds, slugs, and snails – you may want to put some netting or screening over the area to deter birds and put out slug/snail bait.
Planting Inside: Start them inside 4-6 weeks before transplanting outside. Because Sweet Peas don’t like to have their roots disturbed, sow in peat pots. They need cool temperatures to germinate, so find a cool spot like a basement or unheated garage to start them. After they sprout, put them under grow lights or where they will get some sun, but still be fairly cool. Though they can handle light frost, harden them off slowly to avoid shock.
Special Care: Sweet Peas like a deep, rich, fertile soil. Prepare bed 1’-2’ deep with lots of compost or peat. Soils should be slightly alkaline or neutral. Regular feedings recommended. Keep roots cool by mulching and watering regularly during the season. Remove spent blooms to increase bloom period.
Except for the dwarf varieties like Cupid Pink and the bush type, Little Sweetheart, all Sweet Peas require a trellis or fence for support and a sunny area to thrive. They will also do better if protected from harsh winds and in a cooler spot away from the heat of bricks or rock.
Finally, like beans and edible pea varieties, it is a good idea to rotate your planting area at least every three years to avoid the build-up of diseases and pests in the soil.
Note: Sweet Peas are not edible. All varieties are poisonous, especially the flowers and seeds.
Wow, I had no idea you could do them in containers (this is becoming a refrain around your comment box, Fern!).
I also didn’t know that the flowers are poisonous. Thanks for the tip, Shayna.
Excellent advice! Thank you, Fern, and Shayna. This is just what I needed to know.
Mimi — Glad the info was useful, good luck!
Gen —
Shayna — Thanks for providing all that info! I should have mentioned in my review of Botanical Interests that your guys’ website has a huge amount of seed starting and plant growing info.
Great info, I’ve never grown them in a windowsill.
I think you mentioned enough in your review Fern:)
I recently bought some aniseed balls and as i got to the centre of them i kept the seeds and germinated them, and i have just recently put them into small seed trays and all of my aniseed plants are doing well, who would believe it that you could use a seed from the middle of a sweet hey.