Normal? Not really. The Yellowish ones show signs of nutrient deficiency and/or over-watering issues and the purplish ones has either a phos deficiency going on or are cold for some reason. Granted it has only been 3 weeks but such slow growth and discoloration isn't normal.

No soil pests that could be damaging roots? Has it been excessively cold or rainy there? Any idea what your soil temp is? I'd pull the mulch back a bit and see if anything may be going on under there and I'd give them all a dose of fertilizer to see what happens.

Dave

I can't speak for the rate of growth being normal as I have never grown sweet potatoes but it looks like one is showing signs of nutrient deficiency. Might need a boost with a liquid fertilizer with micronutrients.

The purplish ones are ‘Vardaman’ – which has purplish new growth, even per Tatorman’s website. I’m not worried about those. It’s really the yellowish ‘Nancy Hall’ that concerns me.

I gave them a dose of fertilizer a couple weeks ago. If anything the weather has been hot the last couple weeks, (80s to 90s) but it was chilly when I first planted them. I stuck a digital meat thermometer in the soil yesterday, it’s 77F at 4” and that was first thing in the morning.

I wonder if the cool weather after planting cooled the soil off some, to where it’s just now getting back up to warmer temps since the weather has been hotter.

I would pull the mulch back. I try to keep my sweetpotatoes on the drier side because of scurf on the tators.

I can try that...but my garden is weed hell without mulch.

It probably won't be too bad if you only pull it back as far as Dave suggested. Weeds are what made me go to raised beds. Still get them but not nearly as bad. I realize this isn't viable for large gardens though.

different varieties grow at different rates. the mulch is fine. i've grown sweet potatoes with plastic mulch with no scurf problems. the yellow one looks like it has insect damage rather then nutrient issues.

Randy - Its probably both, though the insect damage looks pretty minor. Those leaves are definitely chlorotic however, which suggests nutrient deficiency.

Thanks for all the replies!

Weird thing is, only that one Nancy Hall plant is that chlorotic. The Purple Passion plants, as you saw, have really taken off.

I still don’t think the purple new growth on the Vardamans is cause for concern – even the day I got them, the newest leaves emerging looked that way. I can fertilizer them, though, and I’ll try to take a deeper temp reading.

It’s also getting newer leaves with better color. Perhaps that spot of soil is too alkaline (maybe when I limed, a big “clump” of lime collected there?) or something else is weird. I’ll put some MG or DynaGro (liquid fertilizer) on it.

My soil is a loam/sandy loam in that area, so it shouldn’t stay wet enough to cause any problems. If anything it errs on the too-dry side if I don’t water.

We have been as hot as 97F last week...hard to think they'd be too cold.

The yellowish Nancy looks a little better:

The Vardamans are vining. One of the Nancy Hall plants is starting to vine as well.

Today:

randy4_1, I use plastic mulch also.... to keep the soil dryer. against scurf...not to keep the soil more moist