Knowledgebase

garlic chives are dying #866786

Asked May 02, 2024, 2:25 PM EDT

I am the lead volunteer gardener at the Mitchell Park Community Herb and pollinator garden. I planted garlic chives about 6 years ago. They have spread and done well but last year and again now a section dies off. It can't be from overwatering as we've just started watering. Its only this one section of the garden. I'm thinking of digging up that section, adding leafgro, and replanting some garlic chives there. What's your opinion about what's going on?

District of Columbia County District of Columbia

Expert Response

Hi Amy,


This is puzzling because garlic chives are fairly resistant as a plant, except black aphids, which tend to cause die-back in the fall, and overwatering, which your group has avoided.

Will research and get back to you.


Meanwhile, I would suggest considering a new site for garlic chives, somewhat away from this spot, as far removed as can be managed, preferably sourcing plants from another garden with robust garlic chives. 

An Ask Extension Expert Replied May 02, 2024, 3:57 PM EDT
Thanks for your suggestions. I'll await hearing more from you. 
Amy

On Thu, May 2, 2024, 3:58 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied May 02, 2024, 6:49 PM EDT

Hi Amy,


Fllowing up on your question! Could use some additional information to narrow it down.

Is there any evidence of aphids or thrips, which are super tiny, on any of the plants, or the soil around them? A magnifying glass might be useful . 

Is there any discoloration or other sign of  disease on the  leaves and stems?


Could these plants have been accidentally over-sprayed  from an adjoining garden? Or sprayed to address black soot (that can result from aphid activity)?


Please let us know if you find any indicators.


Meanwhile, black aphids are a common problem with onion family plants and they multiply rapidly, so here are some tips on aphids from our archives in case that turns out to be the issue, or one of the issues.

Many gardens host some aphids. On healthy plants, they don't cause much harm, and beneficial insects, including ladybugs and parasitic wasps, keep them in check. Aphids can become more of a problem when plants are stressed by drought, poor soil conditions, overwintering or overcrowding. Unfortunately, aphids can reproduce at amazing speed and a large colony that can literally suck the life out of your plants. The key to dealing with them is knowing when you need to take action, and then having the right tricks up your sleeve to keep them under control.

How to Identify Aphids: Often the first sign of an aphid infestation is twisted and curled leaves, yellowing foliage, stunted or dead shoots, and sluggish plant growth. Damage is usually most noticeable on shoot tips and new growth, along with unopened flower buds. When you take a closer look at these damaged plant parts, particularly on the undersides of young leaves and developing stems, you'll likely find lots of aphids crowded together.

Aphids range in color from green to yellow, brown, red, or even black. Aphids cause damage by sucking sap from tender plant parts. As they feast, they excrete a sugary substance called honeydew. A fungus called sooty mold grows on the honeydew and blocks light from your plant, but is otherwise harmless. You can wash your plant leaves with water to get rid of the honeydew and sooty mold.

How to Get Rid of Aphids: When an aphid population explodes and begins to cause noticeable damage to leaves, stems, and buds, it's time to act right away. The sooner you can deal with the infestation, the better chance you have of eliminating or controlling the aphids.

Spray with Water: The safest and fastest way to control aphids is to spray them off your plants with a strong stream of water from the garden hose. Aphids are easily knocked off plants and once they are knocked off a plant, they rarely climb back on.

Crush Aphids with your fingers:  If the infestation isn't too heavy, you can squash aphids by gently rubbing your thumb and fingertips over your plants' leaves and stems wherever you see aphids. Check back every few days to see if you need to repeat the procedure. This can be done in conjunction with spraying with water.

Insecticidal Soaps and Horticultural Oils: These controls are low-risk to people and the environment and can be applied to food crops. They'll kill aphids, but must be applied on a regular basis during heavy infestations, and also kill the very beneficial insects that can keep aphid  polulations in check, so this  would be recommended only if the first two were unsuccessful.

.

How to Prevent Aphids: Preventing large numbers of aphids from making themselves at home is possible. In addition to making sure your plants have the water, light, and nutrients they need, here are a few more ways to help keep aphid numbers down. Remove dead stems and weeds from around the plants. You can cover plants with a barrier to insects (like cheese cloth or row covers). You can also grow certain plants nearby to attract beneficial insects like lady bugs which eat aphids (plants like marigolds,calendula, sunflower, daisy, alyssum, or dill).

For more information about aphids and treatment :

http://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html

Please keep us posted on your findings! 

DC Master Gardener team



An Ask Extension Expert Replied May 04, 2024, 10:25 PM EDT

Hi Amy,


Fllowing up on your question! Could use some additional information to narrow it down.

Is there any evidence of aphids or thrips, which are super tiny, on any of the plants, or the soil around them? A magnifying glass might be useful . 

Is there any discoloration or other sign of  disease on the  leaves and stems?


Could these plants have been accidentally over-sprayed  from an adjoining garden? Or sprayed to address black soot (that can result from aphid activity)?


Please let us know if you find any indicators.


Meanwhile, black aphids are a common problem with onion family plants and they multiply rapidly, so here are some tips on aphids from our archives in case that turns out to be the issue, or one of the issues.

Many gardens host some aphids. On healthy plants, they don't cause much harm, and beneficial insects, including ladybugs and parasitic wasps, keep them in check. Aphids can become more of a problem when plants are stressed by drought, poor soil conditions, overwintering or overcrowding. Unfortunately, aphids can reproduce at amazing speed and a large colony that can literally suck the life out of your plants. The key to dealing with them is knowing when you need to take action, and then having the right tricks up your sleeve to keep them under control.

How to Identify Aphids: Often the first sign of an aphid infestation is twisted and curled leaves, yellowing foliage, stunted or dead shoots, and sluggish plant growth. Damage is usually most noticeable on shoot tips and new growth, along with unopened flower buds. When you take a closer look at these damaged plant parts, particularly on the undersides of young leaves and developing stems, you'll likely find lots of aphids crowded together.

Aphids range in color from green to yellow, brown, red, or even black. Aphids cause damage by sucking sap from tender plant parts. As they feast, they excrete a sugary substance called honeydew. A fungus called sooty mold grows on the honeydew and blocks light from your plant, but is otherwise harmless. You can wash your plant leaves with water to get rid of the honeydew and sooty mold.

How to Get Rid of Aphids: When an aphid population explodes and begins to cause noticeable damage to leaves, stems, and buds, it's time to act right away. The sooner you can deal with the infestation, the better chance you have of eliminating or controlling the aphids.

Spray with Water: The safest and fastest way to control aphids is to spray them off your plants with a strong stream of water from the garden hose. Aphids are easily knocked off plants and once they are knocked off a plant, they rarely climb back on.

Crush Aphids with your fingers:  If the infestation isn't too heavy, you can squash aphids by gently rubbing your thumb and fingertips over your plants' leaves and stems wherever you see aphids. Check back every few days to see if you need to repeat the procedure. This can be done in conjunction with spraying with water.

Insecticidal Soaps and Horticultural Oils: These controls are low-risk to people and the environment and can be applied to food crops. They'll kill aphids, but must be applied on a regular basis during heavy infestations, and also kill the very beneficial insects that can keep aphid  polulations in check, so this  would be recommended only if the first two were unsuccessful.

.

How to Prevent Aphids: Preventing large numbers of aphids from making themselves at home is possible. In addition to making sure your plants have the water, light, and nutrients they need, here are a few more ways to help keep aphid numbers down. Remove dead stems and weeds from around the plants. You can cover plants with a barrier to insects (like cheese cloth or row covers). You can also grow certain plants nearby to attract beneficial insects like lady bugs which eat aphids (plants like marigolds,calendula, sunflower, daisy, alyssum, or dill).

For more information about aphids and treatment :

http://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html

Please keep us posted on your findings! 

DC Master Gardener team



An Ask Extension Expert Replied May 04, 2024, 10:27 PM EDT
Yes, you were right! I looked closely   and its indeed aphids. I used a strong hose wash  will do so again tomorrow, and hopefully that will get rid of them. Thanks for your help!
Amy

On Sat, May 4, 2024, 10:25 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied May 06, 2024, 8:56 PM EDT
Hi 
Another question in trying to get rid of aphids. We've "power washed " the garlic chives for 2 days in a row  they've decreased but still present. How many more days should we continue thus route, vs spraying with Neem or another oil/soap?
Thanks  
Amy

On Sat, May 4, 2024, 10:27 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied May 07, 2024, 11:19 AM EDT

Oh, I am so glad you spotted those pesky aphids!


Sounds like you are off to a good start with the ”power washing” with a hose! 
I suggest trimming off any foliage that looks badly damaged to neaten up the plants and remove any possibly diseased parts.

Move to checking the plants every 5-7 days for continued infestation, spray if needed, but ideally predators will move in to feast on aphids. If so, let them do the work! And, you don’t want to knock off their eggs unnecessarily.


EXTRA: If you already have a hummingbird feeder, you could try setting it up in the garlic chives area. This is a long shot since hummer fans set up their feeders super early in the spring before the birds return from their migration south, but might be worth a try. Hummers eat aphids! And other small insects! And they are lovely in the garden!

Be sure to change out the syrup (no dye, please)  frequently enough to keep it safely mold-free. https://blogs.k-state.edu/kansasbugs/2021/10/21/do-hummingbirds-feed-on-insects/#:~:text=Hummingbirds%20generally%20feed%20on%20insects,eat%20insect%20larvae%20and%20eggs.

Happy gardening!


An Ask Extension Expert Replied May 07, 2024, 5:21 PM EDT
Hi again, 
We are a small group of volunteers for an herb/pollinator garden in Mitchell Park, a public park in Northwest DC. I wrote you in early spring and you were very helpful in diagnosing our aphids problem in the garlic chives patch.
We survived the aphids but now the garlic chives patch just doesn't seem to be growing well.  A couple of times over the summer they grew back to more or less normal but then wound up just kind of dying off. Now, you can see that only a few chives along the fence are blooming, but otherwise what should be a patch full of thriving and blooming garlic chives is sparse with a lot of weeds. The patch has been there for probably 5 or 6 years at this point. Any ideas as to what we should do to bring it back to a full patch? I wonder if I should just dig it all up, add new compost and try to replant a bunch of the garlic chives? But if there's an underlying problem, will the same thing happen?
The top photo is what it looks like today, a pretty weed filled section with no blooming garlic chives, compared to last year's photo.
Thanks for your thoughts,
Amy Mates 


On Tue, May 7, 2024, 5:21 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied September 02, 2024, 9:50 PM EDT
They may not be blooming well due to the crowding and competition with weeds and/or possibly being in too much shade (or both). Has the area become more shaded over time? They can handle some partial shade but tend to thrive better in full-sun locations (at least 6 hours per day) and with about 8-10 inches of spacing between plants. You could clear out the area of weeds and transplant several of the clumps, or even collect seeds from those that are flowering and plant the seeds in the spring. 

Christa
Thank you! Good ideas.
Amy

On Tue, Sep 3, 2024, 12:10 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied September 03, 2024, 12:49 PM EDT

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