Any time that you introduce new plants in your home, you are at a risk of infecting the ones you already have. Apparently , when you received the new group of plants, there were troublemakers lurking in them. You should always isolate the newcomers for a few weeks, and then check them thoroughly before introducing them into your collection.
Insects can also come into your home via pets, wind, clothing, cut flowers, etc. As an example: today I was preparing cabbage for cooking, and there must have been several hundred aphids between the leaves. You must have just been lucky in your old home. Good luck.

Yikes, that sounds bad.

Actually I do separate each plant I bring in. That's why I'm curious that after months of being pest free, I have them. I'll have to watch my fresh flowers and the like.

Thanks for help.

The pests can be lurking at very low, unnoticeable levels for a long time. When the plants get stressed (for example, a new environment because of the move, cranking up the heat until the air gets dry, change of lighting due to the seasons, less light and colder windows in your new home, etc.), they become more susceptible to infestation, just like people get ill more easily when they are stressed.

You can easily bring in spider mites or other bugs on your clothing or hands from outdoors. I work for a professional indoor landscaping company, and our plants are generally healthy, but I can't count the number of times someone brings in a sickly little plant from home to put on their desk, and suddenly the whole suite is swarming with fungus gnats and I have to treat every single plant.

where do plant insects come from?

Well when a momma insect and a papa insect love each other...

On top of them coming in on plants or living virtually unnoticeable until they explode you have to take into consideration that your growing conditions may be contributing to their survival and helping them thrive.

Spidermites love dry air and their population will explode in the winter when we artificially heat our homes and the air is dry.

I'll just have to keep an eye on them all I guess. It's so strange that in CO I never had problems. I wish I had my old plants back. I didn't think it would be so hard starting all over with new ones.

Thanks for all you help.

I've learned the hard way not to EVER bring plants into my home from sources that don't specialize in plants -- big box stores, discount chains, home improvement/hardware stores, super markets, etc. Houseplants available from such sources are generally mass-produced in conditions that are ideal for the pests that you describe. It's a problem that's getting progressively worse, & it's destroying the pleasure of indoor gardening for lots of folks.

Mr brownthumb : Why did you tell him that ?????
You know they come from the Plant Insect Stork !

...You know they come from the Plant Insect Stork !

Better known as Home Depot.

lol.

bedelia, I'm afraid that these silly folks are right. You've been 'gifted' with infested plants, unbeknownst to the giver. If and when you are able to rid the plants of the problems, you'll need to be vigilant about preventing it from happening again.

I assure you that they are not springing up out of nowhere, but have been held in a management mode by chemicals (at the growers and probably the garden center). Once the awful chemicals wear off, the population can explode.

LOL...you guys are funny! And I also agree with everyone here. Everytime I walk through a greenhouse and my sweater brushes across several plants, I have this horrible image of hundreds of insects attaching themselves to it and coming home with me. It's every plants growers nightmare **shudder**.

Okay, maybe there aren't THAT many bugs following me home but you get the message. Usually hitchhikers cause the infestations, be it on your clothes, hands or on new plants. It's best to inspect plants thoroughly before taking them home. And then isolating them when you do take them home to make sure a few little 'buggers' weren't in hiding.

As a preventive measure, what I do is spray my plants with soap (palmolive) water daily when they're indoors for the winter, the soap discourages scale, mites and mealies. It works pretty damn well, for me at least. And it is harmless to plants and the environment.

Wow - a lot of information.

I think I'll forget about those Lowes plants for a while. I guess they're not such a great deal after all.

From now on, I'll check my plants more often for those critters.

Thanks for all of the advice.

Depends on your Lowe's. We happen to have a really good garden center in ours and their plants are nicely kept. I buy from them with no worries. Our local Home Depot, on the other hand, is a disaster. A quality nursery is definitely safer, although more expensive.

Can they come from potting soil? I have some plants for three or four years now and they were fine till this winter. All of them are infested with scales, I keep spraying, washing and so on. All those plants were repoted last year, around the same time, I mean probably with the same soil, from one bag. I am waiting for spring to take them all out, remove old soil, wash them well, and try again. Do you think it will help?

bedelia,

Don't let us scare you away from purchasing from Lowes. You could just as easily get pests from buying from a small time nursery or anywhere else. You just have to become familiar with what the pests look like and fight them if you have them when you get home. And even sometimes against all better judgment if I really want a plant and I think it may have pests I'll go ahead and buy it and ask for a discount to make up for the work I'll have to do to make it healthy again.