Fungus Gnats and Mealy Bugs, Oh My

Dear Doyenne,
Hi! I live in Annapolis MD and I have two bug issues:

1) My Ivy plants have these little black bugs living in the soil and I can't seem to get rid of them. This has been going on since the summer and they don't seem to bother the plants, just the people. I have tried a spray on them and it was a temporary fix.

2) At work we have this white stuff on the leaves of a lot of plants and now we have seen the furry little bugs that must spread it. This bug does seem to be harming the plants. Again we have tried several sprays and nothing is working.

I don't want to throw out these plants!! However I don't want the bugs to spread either!!

Thank you,

Chrissy

Chrissy,
Let's take your bugs one at a time.

1)The little black bugs are fungus gnats. They hang out on the surface of open, wet soil. One way to control them is to cover the surface of the soil with small gravel (pea, etc.). See if that works.

2)The white stuff is the excretion of mealybugs. Isn't that special? If the plants are really encrusted in goo, throw them out. Sorry; mealybugs spread quickly. You can't win. If it's not a jade plant, try Safer Insecticidal Soap once a week until the white stuff is gone. Be SURE to spray the plant outside.

Best of luck, KL

Christmas Cactus

Dear Doyenne,
I bought a nice little Christmas cactus at my local florist shop. I chose one that hadn't bloomed yet, but which was just on the verge, with lots of tiny red buds sticking out of the ends of the leaves. I took it home, gave it water (since it was dry), and set it where it would get bright light. I let it dry out between waterings.

It has refused to bloom. Not one bud has developed into a flower.

What did I do wrong?

Amy

Amy,
Believe it or not, it's hard to differentiate between flower buds and leaf buds on a Xmas cactus. I don't mean to insult your intelligence, but more than one expert has been fooled. Did those tiny red buds become anything, e.g., new leaves? It's unlikely you've done anything wrong, it could just be the transition from greenhouse to nursery to home. Best bet is to water consistently (as soon as it's dry on top, it's time), fertilize with each watering at half the recommended dose (use an all-purpose liquid fertilizer) and make sure the plant is away from all heat sources (other than the sun). Sound good?

Best, KL

Avocado Woes

Dear Doyenne,
I have an avocado plant, started from a pit about 7 years ago, now about 2 1/2 feet tall. It spends summers outdoors on my fairly shady patio in New York City, and comes inside in fall. For the first 4-5 years, it was full and lush and healthy, with frequent pinchings by me. In the past few years, despite the same care, it has become gangly and ungainly and the leaves smaller and thinner. Would there be any restorative benefit to cutting it way back (which would entail cutting off all the leaves)? When would be the best time, and how much should I cut?

I would appreciate any help you can give me to rejuvenate my plant. Or is there simply a limited life to avocado trees?

Thank you,

Kitty

Kitty,
Unless you're planning on retiring the plant to Palm Springs, you're right -- it's time to cut it back. Doesn't really matter what time of the year, but I'd wait till the days start getting longer - say, April. You can cut the plant to within 3" of the ground, though you may need a big glass of wine before surgery. Be brave!

Then water and fertilize and don't panic; give it six weeks to show its new buds.

Best of luck, KL

Ivy Topiary Killer

Dear Doyenne,
I purchased two seemingly healthy ivy topiaries on 12/16. I did not over-water or transplant them. They had southern exposure inside on my windowsill in cache pots. They are now dead. What am I doing wrong? This is the second set of topiary that has perished under my watch.

Michelle

Michelle,
Ivy topiaries come from greenhouse environments that are extremely controlled and consistent. Consequently, by the time you buy them, they've become acclimated to high humidity and regular doses of water and fertilizer. In other words, they're notoriously difficult plants to grow in the average home, where life is drier, darker and altogether less consistent than greenhouse life. Also, should you succeed keeping them alive, they're incredibly susceptible to all sorts of pests. My best advice is to try something easier -- how about a jade plant? Seriously, it's just not your fault.

All the best, KL

Scale

Dear Doyenne,
I rescued a stray ficus benjamina topiary from dumpster death six months ago. It was happy in the beginning, new growth, but now it appears to have scale. I've lost almost all of the bottom topiary and the top is looking desperate. It's losing leaves every day. Is there a natural cure for scale? Or is this situation akin to the stray kitty I rescued once that had leukemia? I'd appreciated any advice you send along.

Allison

Allison,
So sorry about the cat, let's hope we can fix the ficus. If the scale is on the leaves, pick the leaves off and throw them away (even if this means denuding the plant). If the scale is on the stems, try suffocating the scale w/rubbing alcohol. Dip a cotton swab in the alcohol and apply to the scale, holding it there for thirty seconds (that oughta do it).

Make sure the plant is away from vents, drafts, central heating, etc. and keep it consistently watered (waiting each time until the surface soil is dry).

Good luck!

Best, KL