Have a question or need help? You have come to the right place. Here you will find answers to frequently asked questions, links to related websites and downloadable documentation. If what you are looking for is not available here please feel free to complete the FAQ form provided and we will do our best to answer you right away!


Can I plant perennials or shrubs in spring/summer/ autumn?

the answer is YES, if it is a pot grown plant.

  • In spring it depends on how far out the plant has come out of dormancy and the frost. if the plant is just coming out of the soil and showing life it can take more frost then a plant that is 'pushed' and has leafs which can get burned by the frost and should be protected under the veranda and 'hardened' off.
  • In summer it really depends on you, the purchaser, on whether you should. We suggest that if it is going to a hot (28C +) and dry season and if you are going to water the perennials by soaking the for 15min each every other day or more if you are in gravel or sand and right up till the ground freezes. Or it could be a normal year and with some rain and you may have to water only once or twice a week till the ground freezes.
  • In autumn you can plant up till the ground freezes, again water when it needs till the ground freezes

There are some exceptions to this rule though, Any plant that is grown in the ground like Swamp Cedars can only be dug in the spring or autumn.

Do we like to be asked questions?

Yes! a question ask is an answer gained. Gardening is about learning, we all are learning. The Spaans family can go back 8 generations of being professional growers and we are still learning. Plants can be complex, but they do not have to be difficult. So ask us your questions because we want you to have success and enjoy your planters and/or gardens.

Do we take trays and pots back?

No, we appreciate the reuse, reduce and recycle. If it stays on this property I can reuse it, once it leaves the Greenhouse property it must be either recycled or thrown out at the customers end.

First, we are a farm so that means we grow many of the plants we sell, with that said anything that is dirty or used that comes back would have to be cleaned in vats of bleach to kill any bacteria or disease or bugs. for example all it takes is one pot or insert to be contact with an impatient with the downey mildew disease and go through our flat filler to wipe out a crop of impatients, which would mean no impatients for our customers. Geraniums, petunias and calebrechoas are affected by ingredients in cigarettes, same thing applies as the impatients.

Secondly, we have specific colours and sizes of pots that fit into trays, when we are growing by the thousands a couple of pots brought back does not make a difference. We understand and appreciate the thought, but we have our specific sizes and colours. Pots from Home Depot, Walmart, Home Hardware, other greenhouses or garden centres etc get thrown out immediately due to the first and second points.

Thirdly, the reason in the spring we move your pots into cardboard boxes is exactly for this reason.... we reuse our trays, as long as they stay on the greenhouse property. so we thank you for your patience in the spring while we switch them over. Some trays are either between 3-5 years old or in some cases close to 8 years old!

Thank You For Understanding.

Does Alton Greenhouses Warranty Plants and Trees?

Alton Greenhouses Warranty

Thank you for your purchase of plants from Alton Greenhouses. Please remember that plants are living entities and need care. Success with your new plant is tied directly to the amount of care it is given. Alton Greenhouses has been in business since 1980 and has been very successful because we are honest and fair in our assessments on guarantee claims. Please call us with any questions you may have about plant care.

Alton greenhouses warranty on shrubs and trees:

One (1) year warranty for one (1) full replacement only. *replacements not guaranteed.

If the warrentied shrub and/or tree was bought on sale the item will be replaced at the price that was paid at initial purchase.

Plants NOT WARRANTY are perennials, shrubs and trees that are zone 5 and over, roses, annuals, tropical’s, plants not planted in ground after purchase or neglected.


  • Plant dies due to negligence
  • Physical damage such from mowers, weed eaters, cars etc.
  • Plants are damaged or killed due to acts of nature such as, drought, frost, ice storms or floods.
  • Plants are killed due to human or wildlife/animal damage.


Alton Greenhouse Perennial & Rose Warranty

Thank you for your purchase of plants from Alton Greenhouses. Please remember that plants are living entities and need care. Success with your new plant is tied directly to the amount of care it is given. Alton Greenhouses has been in business since 1980 and has been very successful because we are honest and fair in our assessments on guarantee claims. Please call us with any questions you may have about plant care.

Perennials and roses do not have warranty.

How do I fertilize my perennials and shrubs?

First is it a sun perennial or shade perennial?

  • I would suggest putting a slow release fertilizer or add compost to the soil. follow the direction on the container or bag.

Second is it an evergreen shrub or deciduous shrub?

  • Evergreen shrubs need a different fertilzer than deciduous shrubs.
  • You can use slow release found in either a spike/ stake or granular slow release. if you have a lot of ground to cover, it might be more cost effective to buy a big bag of slow release than stakes. Although stakes may not get washed out by the rain. Ask us for any clarification or if you have any questions.

How long does it take for a perennial, shrub or tree to be established?

The rule of thumb is 3 years. Remember that it is a very stressful time for a plant to be put into a completly different setting than what it was grown in. the first season is critical, the plant is trying to put roots into the ground just to stay alive. That is why it is important to check for water regularly, use products like MYKES, bonemeal or bloodmeal to promote root growth. If the second year is dry and hot then keep your plants watered they are still trying to get established. By the third year you should be good to go!

The tag says it is perennial, does that mean it is hardy for the Caledon/ Dufferin/ Mono area?

NO! Majority of plants are bred in the USA and the tags are printed in the states and shipped to Canada. so that means because of the breeding to get really awesome colours they are bred for warmer parts of the states. Which makes it important to read the tag and find where it says 'Zone' you want at the most a zone 5. Some zone 6 plants can survive with planning and protection, examples Jap maples, rose of sharon and butterfly bushes.

We here at Alton Greenhouses understand the importance of making sure it is going to be hardy for our climate, if it is not for our zone we sell it with the annuals as an annual.

What does fertilizing plants do? How often should I be doing it?

Every customer who walks in the front doors and sees our baskets, lush and colourful, asks how do we grow them that way? Well ... the main reason is we fertilize.

Since plants, like humans, are alive they need energy to grow and produce flowers and to be generally healthy. Basic biology states that all organisms need a variety of vitamins and minerals to be healthy. A healthy plant will grow thick and strong. Produce flowers by the dozens and has a better chance of not getting diseases or getting 'sick'.

General Rules:

Annual Planters/ Baskets in sun:

  • Plants like petunias, geraniums, calebrechoas, verbena, agreantheums, lobularias etc. get liquid fertilizer every other watering (that could be up to 3-4X a week) OR add slow release fertilizer once for the season and do liquid once or twice a week on top of slow release. The reason being is every time you water the nutrients get washed out so you need to reapply the nutrients to baskets and planters.

Annual Planters/ Basket in shade:

  • Plants like begonias, ivy, coleuses, impatients can be liquid fertilized once or twice a week OR add slow release once for the whole season.
Annuals/Perennial/ Shrub/ Trees in the ground
  • Slow release either in the granular or stake form, apply once after the last frost to last the entire season.

What is a fertilizer? What does it do and is it Important?

Fertilizers are food for plants. Plants require 17 essential nutrients in the soil to survive and to grow. * Found on Fertilizer Canada

So if fertilizer is plant food then the simple answer to that is; It helps a plant to grow, to develop strong roots, to have an abundance of flower, in vegetables it means better harvest and to be overall healthy and fight off diseases.

Is it important? well we believe so. It is why we, for decades, have success with our baskets and containers. We want our customers not only to be successful but to be able to enjoy plants. "We don't just sell, We growfor you"

For more information please visit Fertilizer Canada in our links section under support

What is the difference between a shrub and a perennial?

This is an important question to know the answer to when you are gardening.


When you look at a shrub every year you can see the new growth (green) and the previous years' growth (woody brown). The shrub in the winter will have their branches and trunks because it will come back and continue to grow on the previous years growth. In this case you should choose a shrub that has a nice shape or can be pruned/trained to have a nice shape. ** Do not cut back to the ground!** ask us how to prune your shrubs and when.


Perennials die back to the roots in the winter and re-grow from the roots every year, essentially have a brand new plant every year. In this case if the perennial is split or not looking 'ideal' dont be to worried because once it is planted in the ground, next year it will perk up. Do a light dead heading/ prune after flowering and then in the autumn after plants die back you can clean up.

What is the difference between fertilizer brands?

The difference between fertilizer brands is one of two things. One being where it is made: Canada or USA. Two is it deemed 'Organic'. The actual content should be the same across all brands, for example, a 20-20-20 should be the same whether it is Miracle Gro or Plant Products. Organic fertilizers have to go through programs to be certified by a governing body as organic and usually are fertilizers such as Earthworm casting, Bat gauna, seaweed, Fish, Shell, Hen manure etc.

When and How do I transplant an existing plant to another spot?

The general rule is if it blooms in late summer- autumn transplant in the spring. If it blooms in the spring- early summer transplant in the autumn.

Find the tip of the branches (drip line) and that is how far out you need to start the circumfrence of you circle. The depth depends on the height of the tree and how long it has been planted. A plant in the first year will usually "pop" out versus an establshed plant that won't. if the plant is 5' in height I would say a minimum of 2.5' depth would suffice. You want to get all the main roots... do not severe main roots.

* Remember *

·Do not touch or cram or rip root or drop heavily into hole!

·Treat plant as if it is a baby, check for watering. do not just assume that it does or does not need water.

·Plants are in shock so they wilt for about a week or so.

·Avoid using fertilizer

·Use MYKES, bonemeal, blood meal according to label.

If you have further questions we are a phone call away or come see us.

When do I fertilize shrubs and perennials?

Unfortunately there is no specific date to add fertilizer to your garden. Wait till there is no more threat of frost to add any form of fertilizer. the reason you want to wait is because fertilizer pushes the top growth which is tender, you do not want the frost burning the leaves. Usually the first week of June for the Dufferin/ Caledon/ Mono area is fine but try to watch the forecast is the best thing to do in the spring.

When do I stop fertilizing and why?

Annuals: keep fertilizing till the frost kills them.... get as enjoyment as you can.

Tropicals and House Plants: All through out the year, they do not go dormant and still need energy to survive. Although depending on the variety and the temperature of the room and with what type of fertilizer you are using you may not be fertilizing as much as in you would in the summer time.

Shrubs/ Perennial/Trees: About the first week of August you should stop. August and September you want your plants to start getting 'hardy'. What that means is you want them to get a tougher skin so when the frost and cold weather starts to come they can with stand it and not burn up on you. The roots as well will become hardier and can take the ground getting cold. There are specific fertilizers for Trees and perennials that are applied mid- August to ensure the hardening up of Shrubs/ Perennials and Trees.

Lawn Grass: There are specific fertilizers for every season and there is a general all purpose all season lawn fertilizer.

When do you open?

This is a tricky question for us.

We are growing greenhouse, so that means we are here almost all the time year round. We start growing in February, if you want to see the process of growing every week there is a big difference in the greenhouses, as long as you are ok to just wander you are welcome to visit in what we call our production time.

We are offically open to the public with things to sell about Mothers Day or the week before.

Thanksgiving in October is when we normally put all the shrubs and perennials away and are closed for a week to focus on getting ready for our Christmas Season, which is November to Dec 23rd.

When is the best time to buy annuals?

It depends on if you have a specific plant or colour and can handle bringing them in or protecting them at night. Some customers have been known to come in before Mothers Day to get their specific plant. Usually if you come before or on the May long weekend you are pretty safe for selection. We try our best to anticipated what colours or plants are going to be popular.

When is the best time to plant annuals?

Wait till there is no threat of frost, follow the weather on a trusted channel. There is no guarenteed date of when you can plant. Every year is different, some years we have had frost in mid June, other years mid May had been safe.