Hi @libra
Thanks for your question about your nectarine seedlings.
Why are your nectarine seedlings dying at 8 inches?
Looking at your photos, I'm pretty confident this is damping off that's causing your nectarine seedlings to keel over at around 8 inches. It's a classic fungal disease that hits young plants, and stone fruits grown from pips are particularly susceptible to it.
Damping off is caused by soil borne fungi like Pythium and Rhizoctonia, and what happens is they attack the stem at soil level, causing it to go dark, weaken and eventually collapse. You'll often see the stem looking a bit mushy or discoloured right at the base before the whole plant topples over.
The dead giveaway in your pictures is that characteristic stem damage and the way the plants are collapsing rather than just wilting.
What causes damping off in nectarine seedlings?
The main culprits are overwatering and poor drainage. Stone fruit seedlings absolutely hate having wet feet, and if your compost is staying too moist or doesn't drain freely, you're creating the perfect conditions for these fungi to thrive. Poor air circulation around the seedlings can make things worse too, as can temperature fluctuations if you're growing them indoors or in a greenhouse.
Once your seedlings get to that 6 to 8 inch mark, they're putting more energy into top growth but if the roots haven't developed properly because of wet conditions, they simply can't support the plant anymore. That's when you get that sudden collapse that looks like the plant has just given up.
How to prevent damping off and grow successful nectarine seedlings
Here's what you need to do to give your nectarine pips a fighting chance. First up, use a really gritty, free draining compost mix. I'm talking 50% multipurpose compost mixed with 50% horticultural grit or perlite. This is absolutely essential for stone fruits because they need that drainage.
When your seedlings reach about 4 inches tall, transplant them into individual pots with this gritty mix. Don't wait until they're struggling, get them moved early so the roots can establish properly in better conditions. Make sure your pots have excellent drainage holes and don't be tempted to overwater. Let the top inch of compost dry out completely between waterings.
Here's a top tip that'll help massively: when your transplanted seedlings reach 6 inches tall, pinch out or cut the growing tip. This might seem counterintuitive, but what it does is encourage the plant to put more energy into developing a stronger root system rather than just shooting upwards. With stone fruits, you want super tough roots before you let them get too tall and leggy.
Keep the air circulating around your seedlings and don't crowd them together. If you spot any signs of damping off on neighbouring plants, isolate them immediately.
A word of warning about growing nectarines from pips
Just so you know, nectarines grown from pips won't come true to type. You'll get a nectarine tree eventually if you can nurse them through, but the fruit will be different from the parent and could take anywhere from 3 to 7 years to appear. They'll also likely need a pollination partner unless you get lucky with a self fertile variety, which is pretty rare from a random pip.
That said, there's something quite satisfying about growing stone fruits from pips, even if they're more of a long term project than a quick win. Get that drainage sorted and pinch out those tips, and you should see them push past that danger zone.
More seed growing guides from Garden Ninja
If you're interested in growing more plants from seed, check out these guides:
Hope this helps get your nectarine seedlings through that tricky stage. Let me know how you get on!
Happy growing!
Lee Garden Ninja
Hi @libra
Thanks for your question about your nectarine seedlings.
Why are your nectarine seedlings dying at 8 inches?
Looking at your photos, I'm pretty confident this is damping off that's causing your nectarine seedlings to keel over at around 8 inches. It's a classic fungal disease that hits young plants, and stone fruits grown from pips are particularly susceptible to it.
Damping off is caused by soil borne fungi like Pythium and Rhizoctonia, and what happens is they attack the stem at soil level, causing it to go dark, weaken and eventually collapse. You'll often see the stem looking a bit mushy or discoloured right at the base before the whole plant topples over.
The dead giveaway in your pictures is that characteristic stem damage and the way the plants are collapsing rather than just wilting.
What causes damping off in nectarine seedlings?
The main culprits are overwatering and poor drainage. Stone fruit seedlings absolutely hate having wet feet, and if your compost is staying too moist or doesn't drain freely, you're creating the perfect conditions for these fungi to thrive. Poor air circulation around the seedlings can make things worse too, as can temperature fluctuations if you're growing them indoors or in a greenhouse.
Once your seedlings get to that 6 to 8 inch mark, they're putting more energy into top growth but if the roots haven't developed properly because of wet conditions, they simply can't support the plant anymore. That's when you get that sudden collapse that looks like the plant has just given up.
How to prevent damping off and grow successful nectarine seedlings
Here's what you need to do to give your nectarine pips a fighting chance. First up, use a really gritty, free draining compost mix. I'm talking 50% multipurpose compost mixed with 50% horticultural grit or perlite. This is absolutely essential for stone fruits because they need that drainage.
When your seedlings reach about 4 inches tall, transplant them into individual pots with this gritty mix. Don't wait until they're struggling, get them moved early so the roots can establish properly in better conditions. Make sure your pots have excellent drainage holes and don't be tempted to overwater. Let the top inch of compost dry out completely between waterings.
Here's a top tip that'll help massively: when your transplanted seedlings reach 6 inches tall, pinch out or cut the growing tip. This might seem counterintuitive, but what it does is encourage the plant to put more energy into developing a stronger root system rather than just shooting upwards. With stone fruits, you want super tough roots before you let them get too tall and leggy.
Keep the air circulating around your seedlings and don't crowd them together. If you spot any signs of damping off on neighbouring plants, isolate them immediately.
A word of warning about growing nectarines from pips
Just so you know, nectarines grown from pips won't come true to type. You'll get a nectarine tree eventually if you can nurse them through, but the fruit will be different from the parent and could take anywhere from 3 to 7 years to appear. They'll also likely need a pollination partner unless you get lucky with a self fertile variety, which is pretty rare from a random pip.
That said, there's something quite satisfying about growing stone fruits from pips, even if they're more of a long term project than a quick win. Get that drainage sorted and pinch out those tips, and you should see them push past that danger zone.
More seed growing guides from Garden Ninja
If you're interested in growing more plants from seed, check out these guides:
Hope this helps get your nectarine seedlings through that tricky stage. Let me know how you get on!
Happy growing!
Lee Garden Ninja
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