although its a good practice to quarantine new plants, i haven't been observing it myself. i got this dracaena plant sometimes ago which had some damaged leaves, i took off some of the leaves and decided to keep it separate from other plants for a while. after 5wks i found some mealy bugs on it. so from experience i think 5-6wks should be enough. i'll like to hear other people's opinion though.

Summer,
I don't, although I should. My Mother bought me a cactus when we first moved into our apartment. I inspected that sucker thoroughly and didn't see anything to be concerned about and stuck it near my other outdoor plants.

A couple weeks later, a nearby Hydrangea had ants all over it. I asked a nearby nursery what was causing the ant infestation and they mentioned they're probably attracted to something. Upon inspection, I found these brown bumps and sticky stuff all over the place. I didn't have a clue what this was, so I took a leaf sample to the nursery to ask what was going on with my plant.

Scale! I discovered the culprit, the cactus my Mother bought me. It was covered. It was too late by that time, within a month all of my outdoor plants (aside from my other cacti... that still surprises me) were covered in scale.

Looking back, maybe I should have bought some systemic and treated everything, it would have cost me less than replacing everyone, but oh well. That being said... I was looking at Easter Cacti at HD the other day and found two that had the beginnings of scale. Geez.

My Mother purchased some Sansevieria online from a reputable supplier only to stick them with all her indoor plants. A month later I was looking at one of the Sans only to discover it was covered in mealy bug. Again, too late... the rest of her Sans (ones that didn't even come from that supplier) were covered in mealy bug within a couple weeks.

You'd think I would quarantine by this point.

Planto

I've always thought it a good idea, whether the plants come from a local garden center or from mail order.

I've been a pretty good pest diagnostician for my entire professional career so am able to give any plant a good 'physical ' before bringing them home. BUT, I still like to isolate a plant through a couple of watering cycles and to give them a misting or two of a diluted alcohol spray.

It's sooooo frustrating to end up with a spider mite, scale, whitefly, mealybug, powdery mildew, or fungus gnat infestation throughout the troops! Isolation is not a guarantee, but might provide a little security.

Having said that, it's not enough to stick a new plant in the spare bedroom for two weeks. It needs to be inspected, watered to see if any critters come to the surface of the soil, showered, etc.

P.S. I strongly suggest that anyone serious about enjoying a collection of houseplants take some time to learn what the typical pests look like! There so many websites and books available for us to study. Knowledge of plant care can be self taught!

This post was edited by rhizo_1 on Tue, Mar 25, 14 at 10:09

Unless you're willing to lose or replace ALL your plants (don't know how big your collection is), you really should.

I collect Hoyas & Sans among other things, mealy bugs can RACE thru a Hoya collection. I'm pretty careful w/ new plants (usually place them in the bathroom where I have relatively few plants growing). For several weeks at least.

A fellow GW grower, sweet, generous fellow sent me some Sans last Spring & I didn't really check, figuring he's from GW (my bad, I should ALWAYS check).

Well, I was busy or lazy or both, so I skipped checking the plant &/or isolating it yet several days later, while looking at something else nearby, I saw out of the corner of my eye, the new Sans was covered w/ something, looked like grains of rice, 20 or 30 of them. This was across the room (a small one) from my Hoya collection. I took the whole thing, straight to the garbage, didn't even try to remedy it, or find out what pests they were: too risky! I then had the unfortunate task of informing the Gifter, who then cancelled all swaps/gifts he'd planned for several months. Lucky he's a caring & conscientious fellow!

Lesson learned -- I am always isolating now!!!

IMO, the far larger danger is the pests, not the perhaps less than ideal circumstances of the plant having to be in isolation under imperfect conditions.

Is it wise to isolate? Most certainly. Do I always do so? No. Sometimes the space is simply not there -- particularly if the plant is one that needs to be grown in specific conditions.

Personally, I think it is more important to -- as Rhizo mentioned -- be able to spot and identify common plant pests and the type(s) of damage associated with them.

I have on a number of occasions stopped myself from picking up a plant at a nursery or store because I spotted a mealybug or scale.

In a related vein, there are those plants I won't even bother considering bringing home anymore because, at least in my conditions, they ALWAYS develop pest issues. Ivy is a prime example. For me, ivy has proven to be a major spidermite magnet. Not worth the headache.

Best said by some others is" A clean pant in a clean soil is ideal." Plants that are already clean can grow in more places than it could in an isolation area and grow better.

I try to avoid long term isolation over four weeks longer times in isolation can be harmful to a plant. There are exceptions for time allowed IE: If an infected plant shows improvment I will let it stay in isolation If I enjoy it and plant real estate reasons.
New plants:

I think of it as jump starting a new plant into better health and is the max amount of time a new plant will get in my NEW PLANT isolation area.

When time allows ( Usually the same day not more than three) I remove all old soil examine roots while bare then repot any/all new plants. With freash soil in a new & sanitized pot the new plant is usually sucsessfull in very short time.
On avg if any poblem does exist on a new plant the time is one week before I have the new plant in a better growing area.

Some plants even new plants I have got no days in the isolation area because of the folowing reasons :
1The pest they are subject to getting simply donot exist where I live or other pest that may effect a plant that do exist in this area are not here. ( Think of it as pest control or pest prevention I think I've optioned for the better )

2 The new plant didn't have a fungus or other problems on inital inspection nor any problems with roots during repotting and root inspection.

Prevention includes some plants that I reffer to as sacrifical lambs. When the lamb(s) do well they get the " treatment " with a properly labled product , a make over as sometimes some of the foliage has to be removed, then they go to dinner via a splash of food, watering but in a day or two they get sent right back to the wolves.

Thanks for the thoughts, everyone. :)

I definitely do want to try to avoid letting bugs get near my plants if at all possible. My collection is large enough at this point that it would be difficult to replace if everything became infested. Many of them are sentimental, and some of them are somewhat uncommon plants.

However, I do think that many of us face a dilemma as we become more serious about collecting plants.
The larger your collection becomes, the harder it is to make room for a quarantine area. Plus, the more experienced you become, the more likely you are to want to grow sensitive plants that are not as tolerant of darkness, cold, etc. - so you risk that the new plant may die during quarantine.

For example, I know that my new Croton "Mrs. Iceton" will most likely resent being in the dark, not particularly warm basement area where I am forced to quarantine it, but all my sunny and warm locations are already populated with plants, of course. :)

I have heard of some people resorting to putting a new plant in a plastic bag to quarantine it from other plants in the area even if they can't keep the new plant in a separate room. Do you guys think that those kinds of tactics actually work?
Or is it just wishful thinking to think that you're protecting the other plants by enclosing the new plant in a baggie?

This post was edited by summersunshine on Fri, Mar 28, 14 at 21:03

A plant bag guarantee would be helpful in transporting a new plant home while it travels from climate controlled hothouses to colder cars then to the home it continues to help the new plant adapt to the newer area of the home and could (while in bag) show possible pest problems that MAY HAVE originated in plant or pot prior to opening the bag.
I think of the bagged drive home plant is kind of like leaving a new fish in the bag of water it came home in for a while before setting it free in it's new tank

A pest problem that would require a bag for isolating one or more plants. In short not only do pest like the plant they are infesting they also like the area (environment) the plant(s) are growing in

It's a double edge sword as the bag would also keep pest and the eggs inside the smaller environment in turn could also cause more harm to the plant inside the bag Also considering if are all the pest on that plant that is in the bag

An up scaled version of the baggies is a terrarium plant garden/set up it can be covered at moments to isolate but primarily is for controled environmental plant growing reasons. I imagine this type of set up could also pest protect