6,340 Garden Web Discussions | Growing from Seed
OK, Plan B, for helichrysum -
Surface sow, do not exclude light, @ 75ºF, grow on after germination @ 65ºF , germination in approx 7-14 days from sowing.
(On the surface, do not cover, you said you put them at their specified height/depth, the depth should be on top the sowing medium and just gently pressed in to make good soil contact, then mist to keep moist.)
Sure looks like spider mites to me. But instead of the Murphy's mix (the oil/soap combo has been undermined lately by new research as ineffective - the oil and soap seem to work against each other) try the oil baking soda mix: 1 T light vegetable oil (not olive oil) and 1 tsp. baking soda in a gallon of water and shake well. be sure to get the soil and undersides of the leaves too.
The soil in your photos looks awfully wet too. did you just water? Try letting them dry out more between watering too. But keep in mind that the SM can travel - get the seedlings further away or they will just get re-infected.
Good luck. ;)
Dave
Here's a link with some suggested temps.
Here is a link that might be useful: Hardening off temps.
The white stuff sounds like a type of fungal contaminate called "cobweb mold" and often times be remedied with a little H2O2 (3% hydrogen peroxide) sprayed directly on the contaminate.
The actual mold is growing beneath the surface of the soil and as it's mycelium (fungal roots, for lack of a better term) consolidates control over the soil it can litterally drown the plants by not allowing any oxygen to filter down into the roots where it needs it. Remember, the leaves need CO2 (carbon dioxide) but the roots need O2 (oxygen) to survive.
Most people advocate bottom watering but this often times only perpetuates the damping off diseases such as the one it sounds like you're experiencing.
generally speaking, I don't try to transplant anything until the second or third set of "true leaves" form or when the plant is at least 3-4" tall...so that might have something to do with it.
Also, I'm not really a big fan of jiffy products with the sole exception of their peat moss "jiffy mix" because it tends to be loaded with trichoderma (forest green mold) and occasionally penicillium (blue-green mold) spores.
What I've been doing recently is using coco-coir (which comes in bricks that when mixed with boiling hot water expands into about 3.5 gallons of material and mixing it about 50/50 with jiffy mix. The jiffy mix is peat moss, perlite and pH balanced with lime to offset the slightly acidic nature of the peat moss. I make pots out of 3.5" x 10" strips of newspaper with a Paper Pot Maker and plant in those.
Same net effect and it gives me yet another way to recycle the newspapers my neighbors would otherwise toss in the trash.
Absolutely you can grow these seeds without a mat (tomato, squash, peppers) and many others. They may take a little longer to germinate but they definitely do not need a heat mat.
Most seeds that do require heat to germinate will say so on the seed packet.
And while a lot of seeds will germinate earlier with bottom heat, there are plenty that are hindered by bottom heat as well.
I've been starting a lot of seeds in the house early for many years and have only started using a heat mat the last couple. The only reason I started using it was because I got one for a gift. I will admit though, it is nice to get faster germination on some things. But definitely not a neccesity for most seeds.
We're north of you in Mass and we have in: cauliflower and broccoli seedlings, spinach, kale, radish, lettuce, and mesclun seed. Carrot seeds going in next weekend.
Some kind soul on here pointed me to the site below where you input your last frost date and it will tell you when to plant what.
Here is a link that might be useful: Planting Spreadsheet
I also find it heartbreaking to have to thin out healthy seedlings, so this year I have been sowing seed really thinly. With seeds that I am pretty sure will give near-100% germination (e.g. Amaranthus, tomato, peppers, coleus) I haved just sowed as many as I think I'll need, plus a couple extra. The seedlings grow better from day one as there is less competition around them and they are less prone to damping off.
From my yard I pull healthy, vigorous weeds, in the prime of life, and I do it without a moment's twinge of conscience. So although I sometimes have a fleeting moment of sorrow for the growing-but-not-quite-big-enough seedlings I'm about to yank, I don't see that they are biologically any more worthy than the weeds I discard so cold-heartedly. Sorry, guys: your misfortune is that you grew from the wrong part of the gene pool. Out you go.
