Quarantine Houseplants: should You Separate Plants?

It’s not unusual to quarantine or separate plants when you first bring them into your home. But why do many plant owners opt for this? The answer is relatively simple: quarantining your new houseplants for 40 days means you will minimize the risk of spreading diseases and pests to other plants in the vicinity.

The end result should be an interior space brimming with healthy blooms.

What is quarantine?

To quarantine a plant means to keep it away from other plants for a short period of time. Keen gardeners do this to avoid the spread of disease. Quarantines are used to halt the spread of pests, diseases and other plants such as weeds.

By separating plants for a period of time when you get them, you are more likely to see early signs of pests, weeds, and diseases, allowing you to deal with them effectively before potentially exposing those diseases to all of your other plants.

When to quarantine houseplants

There are a number of times when it’s important to keep separate plants in order to help them thrive. Some of these include:

  • When you bring home a new plant from a nursery.
  • When you bring houseplants inside after they have been outdoors during the warm weather.
  • If you spot pests or diseases attacking your current houseplants.

If you separate plants by quarantining them, you can save yourself a great deal of work in the future as it can significantly reduce the amount of care they require.

When to quarantine a plant?

Plants that are brand new, diseased, or infected should be isolated whenever possible. The simplest way to separate plants, and the most beneficial, is to do so as soon as you bring a new plant home.

Although it’s likely you want to add the plant to a particular room straight away, to inject both color and energy into your interior space, it’s important to stick to the 40 days of quarantine rule.

New plants can never be guaranteed to be pest-free, disease-free or weed-free. If you refrain from separating your plants, new plants may introduce a harmful disease to existing plants. These diseases can actually survive for decades, which will mean other plants will have to fight to survive every year forever after.

Potted plants that develop problems are pretty easy to put into quarantine, although established plants are a bit more problematic.

How to quarantine a houseplant

Before you separate plants, it’s a good idea to take a few preventative measures to prevent the spread of pests and disease. These include:

  • Thoroughly inspect the entire plant, including the undersides of leaves, leaf axils, soil, and stems, for any signs of pests or disease.
  • Spray your plant down lightly with insecticidal soap or soapy water.
  • Remove the plant from the pot and inspect it for any diseases, pests or anything unusual.
  • Re-pot the plant, filling the chosen vessel with sterilized soil. It is at this point that you should separate your plants by placing new plants in a separate room, for a period of 40 days or so.
  • It is important to choose a room that does not have plants in it. This will help minimize the spread of diseases and pests.
  • If this is not possible, you can separate houseplants by putting them in a plastic bag.
  • It’s important to choose a transparent plastic bag and keep it away from direct sunlight, so you don’t cook your plants. Don’t worry, your plants won’t ‘run out of the air’ in a sealed plastic bag, they’re able to produce oxygen and absorb carbon dioxide during the day, and do the opposite in the evening.
  • Whilst the plant is isolated inside the plastic bag, it’s rare it will require any water, like leaves on plants sealed inside a bag lose almost no transpiration or moisture.

What steps to follow after the quarantine period is over

After the separation period is over, you should re-inspect your houseplants again. If you follow this procedure, you will significantly decrease the manifestation of pests, such as mealybugs, spider mites, thrips, fungus gnats, scale, powdery mildew, and other pests.

If you discover a pest problem, it’s a good idea to opt for safer methods of pest control initially, such as insecticidal soaps and horticultural oils. Alternatively, you can use systemic houseplant insecticides, which won’t affect the plant but will help with pests such as aphids and scale.

Alternatives to quarantine

Some of us simply can’t (or are unable to) separate plants and have a period of waiting before adding a new plant to the home or garden. If this is the case, you can opt for an alternative to reduce the likelihood of problems. Some of these alternatives include:

  • Carefully reviewing all plants before bringing them home.
  • Gradually eliminating new plants from their soil.
  • Clean off every surface.
  • Spray plants lightly with soapy water.
  • Shake off any additional water.
  • Re-pot the plant in clean soil.
  • Water accordingly.

While most of these approaches should help to cut the risk of pests and disease, there is no guarantee that it will be successful. However, taking some action is better than taking no action at all, so even these basic approaches can make a big difference to the health of your plants.

Do you really have to put plants into quarantine?

Many ask if it is really necessary to separate plants. The truthful answer is ‘it’s up to you’. However, as you consider whether to quarantine your new plants or not, it is important to take a few factors into consideration. Pests that attack plants can produce an astounding number of offspring extremely quickly.

For example, a single aphid can turn into an incredible 600 billion aphids in a single season. This is a quick way to ensure the majority of your plants lose their health. Ask yourself whether a period of caution is worth a lifetime of reactionary treatment.


Lily Calyx is our in-house flower whisperer, an expert on all things botanical and an enthusiastic orchids collector. She loves discussing the insights of the secret world of flowers, shares her gardening tips and hacks and moons over the latest additions to Serenata Flowers flower range. Ask Lily anything about flowers and we can guarantee she will have the answer.

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