Home Blog FLOWER FOCUS: Growing great sweet peas {part 1}
January 3rd 2014

FLOWER FOCUS: Growing great sweet peas {part 1}

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Now that you’ve hopefully fallen completely in love with sweet peas, blown your entire weekly grocery budget on seeds and the packets have arrived, it’s time to get down to business.


IMG_3195My seeds arrived on Christmas eve and while I really should have potted them up straight away, I only finally got around to digging into the project yesterday. The sooner they get going, the sooner they’ll get blooming!

So far I have about thirty five varieties in the line up and with so much diversity it can be a bit challenging to keep them all in order. I always start by making up tags first thing so there is no way I’ll loose track of the varieties as I get going.


Next I scrounge up a bunch of old jars that’ll be used for soaking the seeds. Each jar gets one variety and its tag.


Then I fill each jar with a couple of inches of water and let the seeds soak for about 24 hrs before planting. This speeds up the process of sprouting and will get the babies growing a bit faster.

You can also nick the seeds with a file to help break their hard seed coat but I’ve found soaking them to be just as effective and way easier.


While the seeds are soaking I get to work filling the pots with soil. This batch required 800 pots so getting a jump on that step always speeds things up the next day.

I use the Sunshine brand potting soil ( Sunshine #4 Organic Aggregate Plus) as my base and then add in a little balanced fertilizer (Nature’s Intent 7-2-4) and some good quality compost, mix them altogether in the wheelbarrow and that makes for a really nice growing medium for the plants.


Sweet peas produce a ton of roots even in the beginning, so the more room you can give them during the early stages of life, the better they will grow in the long run. When choosing a pot, always go for the one with the most vertical length.

Here (left to right) I have a standard 4″ pot, a extra deep 4″ pot and a nursery band pot. The band pot is definitely the best choice!


Once the seeds have been soaked and the pots are filled, it’s time to get sowing! I’m sure there is a more pro method for this part but I always just use a #2 pencil to poke holes in the soil for each seed.

Every pot gets two seeds and then a light dusting of soil over the top before they are placed on 70* heat mats.
A few weeks on the heat and voila, you have babies!


These beauties were started way back in October as part of a new little fall sowing experiment. I’m gunning for the earliest crop to date so fingers crossed that this new method will be the trick.

Tomorrow I’ll share how we prepare our planting beds, set up the trellises, our favorite fertility tricks and more.


  1. Renee on

    After you put the seeds into the pots with damp soil do you keep watering every couple days till they sprout or leave them be? Can’t find this information anywhere!

  2. René on

    How long is the sweet peas season? I have some flowers that are still blooming and it is almost September.

    • Team Floret on

      Sweetpea season can last a long time, depending on the location of your plants and the weather. How great that yours are still blooming!

  3. Amber Brides on

    Hi Erin. I followed your instructions above on starting the seeds indoors. I put 2 seeds in each pot (root trainers). I have never grown from seeds before and I am reading everywhere that they need to be thinned out. I am freaking out a little I guess cause they are shooting up so quickly and I planned on using them all along a fence in my back yard. If I thin them out, Im essentially killing one and so I’m cutting my little crop in half. ugh. bumming out over here. Should I have just planted one seed per cell?? :/

  4. Emily on

    Two seeds in each pot. Do you pinch one out or leave them both and plant out as one clump?

  5. Becky Holmes on

    When you said you started these in October, were they in a heated building. When did you plant them?

  6. Karen on

    I clicked on the link for the seed starter and I could not find the one you use. Do you think the name has changed since you wrote this post?

  7. Julie on

    When and how short do I pinch the seedlings to encourage branching? The seedling have germinated and shot up quickly under grow lights!

  8. David on

    I sowed sweet pea seeds in pots and something is digging a one cm hole and eating the seeds.I put clothe under the pots and netting above and it is continuing.Do you have any idea what it could be?

  9. hMh on

    Thanks for the great post …how deep do you plant your seeds in the pots and then the ground -most sites say 1″ then 3″ apart…. and can you tell me why you used such a low middle number in your fertilizer? is that just to get the leafy greens and roots going as seedlings ? I’m also zone 4a north of Toronto w a short hot summer…if I follow your advice to the lady in Colorado for staggered blooms are the winter series the earliest for flowers? thanks!

  10. Blooming today | A Sonoma Garden on

    […] as plants from the nursery. The sweet peas were a rough growing road, as I dutifully followed Floret’s advise and planted seeds in January in custom made potting mix, placed them on the sunny patch on my […]

  11. Katie on

    I just put my sprouted sweet peas outside in a small makeshift cold frame (from a recycled vinyl shower curtain!) I live in zone 6a, and the temperature is still getting down below freezing at night. How cold is too cold for these babies to be outside? (Thanks for these very helpful posts!!)

  12. Kimberly on

    Will sweet peas grow in hot dry desert? I love them & would love to start them now as it heats up very early in my area. I have a friend in the UK who introduced me to the but they are growing near London. Are some more adaptable to my area near the Mexican border in Texas it zero humidity 90% of the time.

  13. Yara on

    Hi Erin,
    Do you use a liquid fertilizer added to the water while your seedlings are growing? Like kelp? Or is the fertilizer and compost in the soil itself enough? Thank you!!

  14. Cori Jansen on

    HI Erin! Can you tell me what he ideal soil conditions are for Sweet Peas. If you stated it already I apologize. Many thanks to you for taking the time to share with your audience.

    • Floret on

      Cori, download a copy of that book I linked to. It should give you the extra needed soil details : )

  15. Madeline on

    I’m trying sweet peas for the second year. Thanks for all the great information and pictures. I’m ready to start my seeds from Enchanting Sweet Peas.
    Question: Why do you put 2 seeds in each pot? Do they need to be separated before transplanting outside?
    (southeast Pennsylvania 6b)

    Thank you.

    • Floret on

      I put 2 in each because I was low on soil LOL! But if you have plenty, 1 each is great.

  16. zgardengirl on

    Thanks for the response Erin! I just ordered my Winter Sunshine Series…can’t wait to see how it goes. I always grow Mammoth, but think I will add something new to the mix. Thanks for being so inspiring to all of us flower fanatics!

  17. Jenny on

    Thrilled to be reading this. This was one plant that was definitely on my list of must haves!

  18. Kristie on

    I used directions from GFM from a few years back. You have spelled things out in more detail here and I’m sure inspired more people to grow them. My problem was later in the season. We had 6 weeks of hot and humid from June 1- July 15 last year and after just a few weeks my sweet pea stems were only a few inches and then blooms stopped. I’m on Cape Cod so we usually aren’t that hot here but even the Spencers were toast. I may try again.
    How about planting in fall with a low tunnel and pulling that off first of Aprilish? Do you think they would get too tall too early? Zone 7 but this year temps down to 0 a few times already. Would they survive that under a low tunnel? Thx for sharing.

    • Floret on

      During a really hot summer, mine fry in July too. I think the sooner you can get them up and flowering the better your results will be.

      If you gave the hoop house ones extra protection during really cold spells I bet you’d have great success. It’s worth a shot! They can take some pretty cold weather.

      You could also get them going in pots in the fall and plant out big beefy transplants in the hoop once deep freezes are past. Like by early March?

  19. zgardengirl on

    So loving your posts and recommendations for growing Sweet Peas, so thank you! I am zone 4a in the Colorado Rockies, so I usually start my sweet peas indoors in late March. I am unable to transplant outdoors until early June, and I just find my plants become overgrown and unmanageable if I start them an earlier. I have 2 questions for you: 1) It seems like my sweet peas always bloom in mid-late summer, and would love to see an earlier flowering. I have not tried any Winter series. Is this something you would recommend for my area to have an earlier flowering? and 2) Do you fertilize your seedlings after germination but before transplanting, if so what do you use?

    • Floret on

      The winter types will bloom quite a bit earlier than your later varieties. If you could, I would plant a winter group (I ADORE the Winter Sunshine Series from Owl’s Acre Sweet Pea or you could do Winter Elegance) then a mid season group (either Mammoth or the Spring Sunshine Series and then follow with a big wave of Spencer’s. That would give you a really long window of bloom for sure!

  20. Anouk Dupraz on

    Hi Erin. Thank you for those beautiful pictures! A real pleasure during the cold and wet winter days waiting for spring… I’ve followed your precious advice on growing sweet peas, and the results are… amazing long stems, much better than what I had before. I plant them in fall, add some vermicompost, cover them end January to help them survive cold February days, and uncover begin of March. Plants then have a big root system and are quite “fat”.And as you say ” water, water, water “. A real success ! Thank you so much and happy New Year!

    • Floret on

      Thrilled to hear it!!

  21. Shanti on

    you didn’t mention getting the winter/spring sunshine series from Gloeckner’s – any problems with these?
    Thanks so much for sharing all this info, you are a rockstar

  22. Shelley on

    Thank you Erin for sharing this information! Love the photos. I am anxious to try these flowers (and others) out. I live in NE Texas, zone 7. When do you think it would be too late to get the seeds started (can the flowers stand the heat)? I don’t even have the seeds yet. :P Thanks!

    • Floret on

      Shelly, the TX growers I know (Pamela and Frank Arnosky) had theirs in full bloom when we visited in early March. It may be too late unless you have some way to shade them.

  23. Hedgerow Rose on

    I knew I was saving all those bands from my roses for a reason! :)

    Usually I direct sow my sweet peas in the ground as soon as soil can be worked (I’m in zone 6 so this is pretty late in the game.) I’d love to try your method and get a jump on them, though, so do you recommend starting them in the greenhouse a few weeks prior to when I’d normally sow the seeds outdoors?

    Thank you for a great series!


    • Floret on

      Laurie, I try and sow them in pots as early as I possibly can. If you can manage, I’d do them now and then you’ll have big beefy plants to put out by spring. Then follow with your d/s crop for a nice stagger.

  24. Susan (UK) on

    I discovered your site yesterday via a Re Tweet. Its beautifully put together and very interesting. The sweet peas are stunning. I’ll definitely be following your instructions.

  25. Chelsey on

    I am so excited learning all of this from you. Your generosity in sharing your knowledge is so incredible, thank you! I can’t wait to follow your season again this year.

  26. Michelle on

    Can’t wait to stay some sweet peas! Erin, you rock!!!

  27. Kris P on

    Thank you for sharing all the details of your approach. This is invaluable!

    • hopflower on

      You don’t have to pinch winter-sown ones.

    • Floret on

      I’ve done it both ways.

    • Floret on

      I do some seasons and then others I forget. It’s always so hard to nip them back at such a young age!

  28. webb on

    Thanks so much for this info. Have wanted to try sweet peas for a long time, but had no idea how to start. Clearly, this isnotthe right year to do it, but ican be patient!

    Hope it’s a good growing season for you. webb

    • Floret on

      Oh, you should give it a go! You won’t regret it, promise : )

  29. Alexandra Jusino on

    I’m loving this series, I’ve been trying to figure out for a year when and how to plant my sweet pea seeds and I’ve learned so much. Do they like to be in wet soil when you set them in the warming mats? I’m in Chicago so I will have to wait til the ground thaws in two months but I can at least start the seedlings soon

    • Floret on

      I water the pots well and then make sure they stay moist but not soggy. Basically no standing water in your tray below or you could accidentally rot your seeds.

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