To have lady beetles stay around you need to provide a proper habitat that includes food (aphids), water, and shelter. It also means not spraying anything toxic enough to harm those lady beetles. You can help them help you control the aphids with sharp streams of water to knock the aphids off the plants.
An aphid problem of the magnitude you describe indicates a soil problem. Find someplace that does a good, reliable soil test for base nutrient load and soil pH levels (I know AgCanada does not do this, same on them) and dig in with these siple soil tests to see what you have and waht needs to be done top make your soil better;

1. Structure. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. A good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top.

2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drains too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up.

3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart.

4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer you soil will smell.

5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy.

I believe Garden's Alive will ship ladybugs, possibly also Gardener's Supply. Both would probably insist on overnight or second-day shipping. There may be other sources also - try googling. I know, when I lived in San Francisco, the better nurseries had boxes/bags sitting on the counter in the spring. To get them to stay around long enough to lay eggs and do you some good, you have to feed them, Otherwise, they just fly away looking for food. You can buy a food for them - ask when you buy them - or you can plan ahead in the future and plant the flowers that they feed on, as well as maybe getting the lure/food again. Any you find can be placed on the affected roses, but they don't always stay and lay eggs, even with all the aphids - that one may have been a male....

In the mean time, as Kimmsr said, a sharp stream of water will knock them off - they don't climb back, but the ones you didn't get will still be there, so it's not a one-time job - you have to do it for several days, and then keep an eye on the roses for more aphids as the days pass. You can use an insecticidal soap on aphids - I don't know its affect on roses, so read the label. Pyrethrins and neem oil will also kill aphids, but all three of the last will also get ladybugs, so be careful when using any of them.

And last, cut back a bit on the fertilizer, as excessively fertilized plants can attract aphids. I assume you are using organic fertilizers, which are lesser offenders, but if you have lots of aphids, then something is attracting them to the roses.

Roses are extremely attractive to aphids, period. It's one of facts of life that rose growers learn to accept....or they stop growing roses! Sad, but true.

If you have lots of roses, then the water sprays just aren't going to help much, as you probably already know. The introduction of ladybugs to a outdoor garden center is usually less than satisfactory, but worth a try if you are interested in the experimentation.

Of the pesticides suggested earlier, I recommend Neem oil. It has a very limited effect on beneficials, and then ONLY if you spray the neem directly on them. Chewing, rasping, and sucking insects (like aphids) ingest the Neem allowing it to do its job. Insects stop feeding fairly quickly, though they remain on the plant until they die. Neem stops the aphids from reproducing, as well. Neem also has also proved very effective against certain fungal diseases, including powedery mildew and black spot!

Once you get the aphids under control, the ladybugs will be better able to keep them there. There are many reputable on line places to purchase ladybugs. Mail order is best, so I hear. The beetles don't exactly have a long 'shelf life'.

Agree with everything that's said here.

Planet Natural has ladybugs for 16.50 for 2000 of them...free shipping. I don't know if that includes Canada or not. Another bug is the lacewing, aka, "Aphid Lion," because it eats aphids.

I ordered some of those last year (trying to kill larvae of other bugs) and I was too late into my infestation, but I had a good time with them. I think I got those from Planet Natural. Was happy with them.

Ladybugs are a common insect and sometimes they're everywhere. I wouldn't buy them just to get rid of aphids. As Kimmsr says, a blast of water gets them off. If the leaves fly off with the aphids then they've gone too long and the plant is weakening. Neem oil, with a little soap to get it to mix with water, really puts a hurt on the aphids. Great on white flies too. It doesn't seem to bother hard shelled insects and definitely doesn't bother the plant. Another thing, to strengthen your roses put a little (1 Tbs)epsom salt around them and water it in. Watch them for a week. I can almost guarantee there'll be a big difference. And finally, again as Kimmsr says, get the soil healthy. His techniques have saved my veg garden in a big way.

Tessie,

If you are in Vancouver, find a hydroponics store close to you or ask at a pot cafe. They should know. Many marijuana growers use ladybugs for their plants so find out where they buy them.

I'm going to go ahead and brag a little here. I planted wild plums and beach plums maybe 4-5 years ago, and they're finally going to produce this year. I was looking at the baby plums last week and saw wilty leaves on a branch tip- they were covered with aphids. I kept looking... more aphids, more aphids... ooh- a ladybug. And another ladybug.

I remember that last year they were mating all over these shrubby trees. Must be like the seedy motel for ladybugs or something. I should try and get a photo of ladybugs munching on aphids this weekend.

OMG, they have pot cafes in Vancouver??? I thought those were just in Amsterdam.

I've been gardening organically (no fertilizers, pesticides, herbicides, etc., only free organic inputs) for almost two years. I had a ton of aphids last year on my roses and I went out every couple days and squished them off of nearly every new bud. This year I have them again, but it seems like they aren't on nearly as many of the buds.

I have another plant growing (some sort of weed I imagine) that is covered with black aphids (the roses have green aphids). When I first noticed the aphids my first thought was to cut it down and dispose of it, but I found it interesting that there were ants tending to the aphids. I've read about how ants will "farm" the aphids for the honeydew they secrete and I was interested. So I decided to see how things went if I didn't intervene.

Yesterday I was checking on the black aphids and I noticed a single ladybug on the plant, and it didn't take long for me to find the eggs it had laid. I looked at some pictures online and verified that these were in fact ladybug eggs.

It makes sense that to encourage predators of "pests" such as aphids you must first have pests, and you must second maintain at least a small level of the pests as food for the predators.

I plan to keep watching progress of the ladybugs. Hopefully they will grow in number to cap the growth of the aphids at a reasonable level and I will continue to resist the urge to intervene.

I hope that you too can be open to the possibility that sometimes doing nothing is the right thing to do.

-Kyle

The trouble with buying ladybugs is that most of them will probably fly away to other peoples property.
If you were in California I would say go take a hike up ice house canyon by Mount Baldy, the place is infested with swarms of ladybugs.

Last week I bought and released over a thousand ladybugs on a cherry tree filthy with black aphids. They all flew away!

Although today I saw a ladybug on my cherry tree happily munching aphids. Maybe some will come back to feast and then start families.