Return to the Growing from Seed Forum | Post a Follow-Up

Begonia Woes........

Posted by cugal 5b-6a NE Ks (My Page) on
Tue, Jan 28, 14 at 17:10

Just sowed about 500 pelleted seeds of wax (fibrous) Ambassador F1 begonias........ I'm allowing 14-16 weeks from my LFD (May 1) for the plant out date......

Surface sown in a flat of Pro MIx BX, misted & covered.... placed under a 4' T8 2 bulb fixture (on 16 hrs/day)..... on heat mats (77F), in a germinator......

Fastforward to January 28Th........ Seeds are germinating well, but when they're placed under lights, most die. They're watered properly & media temp is 65F D/ 60F N....... Any ideas?

Follow-Up Postings:

RE: Begonia Woes........

Hi cugal,

Well, I’ve never used Pro Mix BX but to the best of my knowledge it’s mostly sphagnum peat moss and contains no fertilizer. Mixes that contain a lot of peat can stay wet for a long time; make sure you're not over-watering. Also, if you haven’t added any fertilizer to the Pro Mix, that may be the reason the plants are not doing well. I’d suggest adding a good well balanced, water soluble, fertilizer. While the seedling are really small, you’ll need to dilute it to about one fourth strength. Maybe check with those in the Begonia forum (see link below) to see what they suggest.


Here is a link that might be useful: Begonia Forum

RE: Begonia Woes........

  • Posted by cugal 5b-6a NE Ks (My Page) on
    Tue, Jan 28, 14 at 22:24

Thanks Art for your input! Yeah, I had planned to use Fafards 3B when potting up, but failed to get that far......... Adding diluted fertilizer may help....... I'll give it a try!

RE: Begonia Woes........

I tried begonias for the first time last year and it was a total loss. They germinated well, a few managed to get up to the size of a dime (after a very long time) but they all eventually died. After more research I decided it was the soil mix. Begonias prefer a very coarse mix, I was using Jiffy seed starting mix. I have grown a lot of different things from seed successfully, but Begonias do have special needs.

This site is helpful.

Here is a link that might be useful: Brads Begonia World

RE: Begonia Woes........

  • Posted by cugal 5b-6a NE Ks (My Page) on
    Wed, Jan 29, 14 at 10:54

Thanks mandolls for the link & helping me sort this thing out! My results have been the same as yours, so I guess misery loves company! ;(

rhizo_1 gave me some very sound advice when I decided to try Begonias & I've tried to follow that......... She(?) suggested starting seeds in finer media (Pro Mix) & potting up to a "barkier" mix. It's been suggested my lights might be too close (3-4") to the flats, so that's one of the things I'm looking at. My plant out date is the first week of May, so time is of the essence.....

RE: Begonia Woes........

Hi again cugal :-)

Regarding your lights, I don’t think they’re too close at all. In fact, I’d say most folks keep them closer than 3 or 4 inches. Those T8 bulbs don’t get hot enough to be a problem, I’ve used them for years and have always kept them about 2 inches above the seedlings.

In all probability, your main problem is the growing medium. As mandolls has mentioned, begonias prefer a coarse, well drained growing medium. I think Pro Mix has too much peat moss and, as I mentioned earlier, no nutrients what-so-ever.

Regarding nutrients, some folks will advise not fertilizing seedlings until they have developed a set or two of true leaves. However, many disagree with that, including the University of Massachusetts (see link below).

Whatever corrective course you end up taking, I wish you the very best of success!


Here is a link that might be useful: Fertilizing Seedlings

RE: Begonia Woes........

  • Posted by cugal 5b-6a NE Ks (My Page) on
    Sat, Feb 1, 14 at 14:14

Thanks again Art for the link & your insight! And yes, I'm inclined to agree with you about the media issue. Pro Mix retains water, staying far too damp when bottom watering..... I've potted on (the few that survived) to Fafards 3B...... We shall see!

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Growing from Seed Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here