Hello. I recently purchased a 4" pot Lemon Verbena plant. It was very healthy until I brought it home. Within 2-3 weeks of transferring it to a terracotta pot (not too big or small for it's size) it has developed blotches in it's leaves; tiny green insects (I suspect they are spider-mites) have appeared on some of the delicate stems and the tiny buds that were forming at the top of the plant have withered away and died. Also, the terracotta pot has circles of white furry mold growing on the outside! I kept the plant in my kitchen which is warm but does not have direct sunlight. Today, I put the pot outside hoping that the blotches and mites might disappear!
What on earth has happened? The garden centre fellow told me not to over water it so I have done exactly that. I have been desperate to grow this plant ever since it was introduced to me last year. I am an absolte novice to anything green and gardening and would be grateful for simple and straight-forward advice on what I should do to save my plant.
-
hendi_alex
- Super Green Thumb
- Posts: 3604
- Joined: Sun Jul 06, 2008 7:58 am
- Location: Central Sand Hills South Carolina
The insects are likely aphids, as spider mites are reddish brown and almost too small to see. They also cover the leaves in very fine silk that can be seen when looking at the leaf at the right angle in good enough light.
I suggest that you take the plant from the soil and wash the roots, just in case the soil has some fungus or other rot in it. Flush to top of the plant with vigorously running water until all of the aphids are washed away. Repot the plant in a suitable container with fresh sterile soil, then move the plant to a filtered light location outside, to be left anytime the night temperature stays above 40 degrees or so. After repotting, if the plant shows signs of wilting, snip as much as 1/3 or the top growth off, so that the roots are not overtaxed while they try to get re-established. Gradually move the plant into full morning only sunlight, over several days to a week and a half. Then gradually move the plant into all day sun, as long as it doesn't dry out too much in the sun and heat. If it tends to dry too much, then move the verbena back to morning sun only. Lemon Verbena gets pretty large, so up pot the plant as its size increases, but never increase the pot size more than will give about two inches additional soil around the root ball.
I suggest that you take the plant from the soil and wash the roots, just in case the soil has some fungus or other rot in it. Flush to top of the plant with vigorously running water until all of the aphids are washed away. Repot the plant in a suitable container with fresh sterile soil, then move the plant to a filtered light location outside, to be left anytime the night temperature stays above 40 degrees or so. After repotting, if the plant shows signs of wilting, snip as much as 1/3 or the top growth off, so that the roots are not overtaxed while they try to get re-established. Gradually move the plant into full morning only sunlight, over several days to a week and a half. Then gradually move the plant into all day sun, as long as it doesn't dry out too much in the sun and heat. If it tends to dry too much, then move the verbena back to morning sun only. Lemon Verbena gets pretty large, so up pot the plant as its size increases, but never increase the pot size more than will give about two inches additional soil around the root ball.
-
applestar
- Mod
- Posts: 30543
- Joined: Thu May 01, 2008 7:21 pm
- Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)
I agree. Aphids LOVE Lemon Verbena and that's your current pest. But it's also true that red spider mites will infest the plant -- especially later in the winter since you will need to bring it inside during the cold weather.
Look at it in really good light and you will probably see the aphids -- they can rapidly wither new buds. I sometimes use flat soft water color brush to brush them off the delicate buds. If you spray first with water, they will shift around and it will be easier to detect. They have excellent camouflage.
I agree with most of the advice given so far, but the key point is that Lemon Verbena NEEDS sunshine or really good supplemental light when kept inside. They really do best if you can plant in the ground after gradually acclimating to the sun and wind (hardening off), then dug up and potted in the fall to bring inside (it won't survive our NJ winter outdoors).
One detail that I don't entirely agree with is that the soil needs to be washed off. Most newer premium potting soils contain micorrhizae (beneficial fungi) and CAN develop mold-like furry growth. I think just putting it outside (definitely "warm enough" now
) starting in a shaded spot and hardening off into direct sun would be sufficient.
Look at it in really good light and you will probably see the aphids -- they can rapidly wither new buds. I sometimes use flat soft water color brush to brush them off the delicate buds. If you spray first with water, they will shift around and it will be easier to detect. They have excellent camouflage.
I agree with most of the advice given so far, but the key point is that Lemon Verbena NEEDS sunshine or really good supplemental light when kept inside. They really do best if you can plant in the ground after gradually acclimating to the sun and wind (hardening off), then dug up and potted in the fall to bring inside (it won't survive our NJ winter outdoors).
One detail that I don't entirely agree with is that the soil needs to be washed off. Most newer premium potting soils contain micorrhizae (beneficial fungi) and CAN develop mold-like furry growth. I think just putting it outside (definitely "warm enough" now
) starting in a shaded spot and hardening off into direct sun would be sufficient.