I have learned to eliminate aphids by necessity throughout the different stages of my plants’ life cycle. I would even go so far as to say that I have a special relationship with aphids.
I have learned a lot and will know more next year. Still, for the first time, I am winning the battle.
This short guide is a step-by-step account of how I deal with aphids on my vegetable and herb garden plants.
This article is more of an approach to dealing with aphids than a fix because I have yet to find a quick fix for getting rid of aphids permanently.
When aphids get a hold, they always seem to find a way; it is the start of a relationship that will last weeks to months.
In the best of worlds, we prevent aphids from attacking our plants. Stressed plants are more susceptible to pests and diseases, and if you create a perfect growing environment, you may be successful. If so, well done.
Tried and tested methods for dealing with aphids (organic fixes)
1. Dealing with aphids on seedlings
I start my vegetables and herbs from seeds or cuttings, and in early spring, I have plenty of seed-starting trays and nursery pots on the go.
And I always run into space issues waiting for the outside temperature to warm up.
Tomato seedlings growing fast and eggplants needing a minimum soil temperature of 12 degrees Celsius / 55 degrees Fahrenheit are just two examples of plants that always get me scrambling for space.
I typically move some plants to a halfway home in our greenhouses or conservatory. Here, the temperature and humidity fluctuate in early spring, and seedlings easily suffer some stress.
This is usually my first encounter with aphids. And I always detect them through manual inspection.
Treatment of aphids on seedlings:
- Isolate infested seedlings
- Daily manual inspection
- Manual removal of aphids
- Check the soil for aphids
Inspect leaves carefully, watch for discolorations, and always check underneath the leaves. Remove aphids manually.
Also, check the soil in your pot for aphids falling off your seedlings during the manual inspection. Look closely. If you have found aphids on the plant, there are often aphids that have fallen off the plant into the pot.
If you catch the infestation too late and start seeing curling leaves and stunted growth, consider destroying the seedling. Do not compost.
I rarely have to destroy seedlings due to aphids, but it does happen.
2. Light aphid infestation on young plants
If you are like me, you overseed to ensure you have enough plants. Consequently, it is common to have more young plants in early spring than we planned to grow.
This leads to plants getting crowded and poor air circulation, and just like that, aphids appear out of thin air.
Treatment of aphids on young plants (light infestation)
- Isolate infested plants
- Daily manual inspection and removal of aphids
- Inspect young leaves and top formations closely
- Spray with water if the plant is strong enough
- Use soap and garlic spray or Neem oil and water solution
Inspect young plants paying extra attention to fresh new leaves and top formations. Aphids love to feat on new growth and often hide in new growth yet to open up.
Young leaves that are yet to open up can be dealt with in two ways.
- If possible, gently open up the leaves to inspect for aphids and brush them off if found. Do not squeeze young leaves, as you risk damaging the plant.
- Use your fingers to open the top formation and blow to remove any aphids. Remember to check the soil for aphids falling off.
If your young plants are strong enough, consider spraying them with water. To be effective, you need a moderately strong spray why this is not always a good alternative for young plants.
For example, young pepper plants are usually sturdier than young tomato plants. But regardless, be gentle to avoid damaging your plant.
If all else fails, use my proven soap and garlic spray or Neem oil and water solution. Always spray early morning or evening as
3. Heavy aphid infestation on young plants
You may fight a losing battle if you catch a young plant with a severe or heavy aphid infestation. You may be able to remove the aphids, but the damage may already be too severe.
This happened to me earlier this year when I forgot to check on a plant moved to the side. When I found the plant, it was riddled with aphids, the top was bent over, and the plant even looked in pain.
I did not try to save this plant as the top formations were too damaged.
But, when I try to save young plants heavily infested with aphids, I follow 3 simple steps, as the plants are beyond manual inspection and removal.
Treatment of aphids on young plants (heavy infestation)
- Isolate plant
- Consider gently spraying the plant with water
- When dry, spray with soap and garlic spray or Neem oil and water solution.
The process must be repeated several times over a few days to be effective. And always spray your plants early morning or late evening and protect the plants from direct sunlight.
4. Light aphid infestation on mature plants
Mature plants lightly infested with aphids are relatively easy to treat. Here the real challenge is accessing the plant and isolating it if not growing in a pot or container.
Manual removal is not always feasible as aphids can be challenging to spot, and plants can be difficult to examine closely.
Aphids prefer fresh new growth, and you are most likely to find aphids in the top part of the plant.
Treatment of aphids on mature plants (light infestation)
- Isolate plant
- Spray the plant with water
- When dry, spray with soap and garlic spray or a Neem oil and water solution.
If your plant is growing in the ground or a raised garden bed, use floating row covers to isolate the plant from the rest of your garden.
I use my trusted long-reach garden hose nozzle sprayer to spray the plant with water.
My manual pressure pump sprayer is ideal for applying soap and garlic sprays and Neem oil and water solution.
Evaluate the situation and consider destroying the infested plant, as there is always a risk that the infestation will spread to the rest of your plants.
I would consider destroying the plant if it, for example, is one of many eggplants and grows close to my priced Bhut Jolokia ghost peppers or scotch bonnet pepper plants.
Repeat the process several times over a couple of days. Always spray plants early morning or late evening and protect the plant from direct sunlight.
5. Heavy aphid infestation on mature plants
If one of my mature plants suffers a severe aphids infestation, I ask myself the following questions:
- Is the plant one of a kind or one of many?
- Is it realistic to try to rescue the plant?
- What risk does it pose to my other plants?
- Is the plant early or late in its life cycle?
I will always try to rescue a plant if it is one of maybe 2 or 3 plants.
On the other hand, if it is one of 10 or 30 plants, I will destroy it if it suffers from a heavy aphid infestation.
In situations where I am undecided, I evaluate the damage done to the plant, the risk it poses to my other plants, and whether it is early, mid, or late in its natural life cycle.
If I decide to destroy the plant, I remove it and leave the spot open for at least a week before planting another plant in that same spot. The infested plant is destroyed and never composted. If I decide to treat the plant, I follow the listed steps.
Treatment of aphids on mature plants (heavy infestation)
- I spray the plant using a garden hose nozzle sprayer with adjustable pressure. I set the pressure as high as possible without risking damaging the plant.
- Next, when the plant is dry, I apply the soap and garlic spray or Neem oil and water solution using a manual pressure pump sprayer.
Other commercial alternatives for dealing with aphids exist, but I have never felt comfortable using them. I grow plants for consumption, and that’s where I draw my line.
Manual inspection is the key to finding and treating aphids
Manual inspection is a process, not a task.
Inspect your plants daily or as often as possible, and look for discolored, disfigured, and curling leaves.
And pay extra attention to fresh new growth. Aphids are small and can be hard to spot why looking for the damage they cause is helpful.
Where I garden, aphids are hard to avoid altogether. But if they are found early, they are relatively easy to treat and get rid of.
Find them too late, and it may cost you several plants.
Helpful sources:
[1] https://www.researchgate.net/publication/298786153_Biology_and_Ecology_of_Aphids
