We help gardeners with gardening questions.

• Hardening Off Plants
• Companion Gardening
• Logs in Raised Beds
• How to use Compost Tea

Best Practices & Soil

Question: Hardening Off

I have been told that I need to “harden off” my plants.  What does this mean?

Answer:

“Hardening off” is the term used to describe the process of preparing bedding plants that have been grown indoors or in a greenhouse for outdoor conditions.  Bedding plants grown indoors have been growing in comfortable conditions and can go into shock if planted outdoors without having a chance to get acclimatized.  This process involves at least a week of gradual exposure to outdoor conditions.  Start by putting the plants in a shaded, sheltered location for 2 to 3 hours the first day and gradually increase the number of hours and the amount of sunlight by one to two hours over the next five two seven days.  Bring them back into the house or preferable a shed or garage until they can be left outside overnight for a couple of days.  Be prepared to bring them in if there is a risk of frost.  Reduce water and don’t fertilize during this “hardening off” period.  Once the plants have toughened up and the risk of frost is past, they can be planted out.  Choose a calm, partly cloudy day if possible, make sure to water the plants and the planting hole and move the plants into their summer spot.  You can water them in using a transplanting fertilizer solution to give them a good start.

Question: What is Companion Gardening?

I am confused as to how one can “companion garden”. Does this mean that you grow certain types of plants beside each other or intermixed with one another? So for example beans and cucumbers, would you mix the seeds up and plant all at once or would you plant a row of beans and then the next row or beside this row, or in the case of a square-foot garden, do you plant them beside each other in their own ‘plot’? I know that this is probably a silly question but in using the most amount of space I hate my corn taking up so much space.

Answer:

Companion gardening means growing certain compatible edible plants beside one another. That is not to say growing them in the same row.
It is a method of growing edibles so that they may benefit from one another and thrive. Some plants simply do not like growing close to one another and by planting them close together will not produce as good a harvest. Some examples of planting vegetables that are in the same family, ie. nightshade family; tomatoes, eggplants and peppers, but potatoes also belong to this family and do not like being with their relatives. A perfect example too, is the “three sisters”, where one plants corn, beans and squash together. The corn offers the “poles” for the beans to climb, the beans offer the nitrogen for the other two plants, and the squash provides a ground cover offering shade to the other plant roots so they do not need to be watered as often. Also, covering the soil so that weed growth is minimized. This would be a good example for you to follow for growing your corn.  Another example is cucumber, they do not like being close to potatoes but do fine by peas, beans and nasturtiums. In square-foot gardening one would plant one square of tomatoes and the next square of peppers, but not potatoes.

Question: Should I use Logs in Raised Beds?

I have built a raised-bed garden – three by nine feet by twenty inches deep. Someone suggested I put some logs in the bottom of each bed to take up space and help drainage. We have a number of balsam trees that have died and I am wondering if it is a good idea to put pieces of these in before filling with soil.

Answer:

As Balsam trees are an evergreen and of the fir family, they would lower the pH of the soil causing the soil to be more acid based. Depending on what you wanted to plant in the garden it might be good to use these logs, for example, for Hydrangeas, which do very well in acid-based soil. But if this garden is to be used for vegetables the recommendation would be to not use the logs as a base as vegetables enjoy neutral pH soil. One can order a four-way mix soil by the yard, delivered, to use in this garden bed. Doing so would be the favourable option and recommendation.

Question: Using Compost Tea

I have a Morden rose bush that has been a challenge.  Last summer it grew very tall, 4 to 5 feet, but did not produce a single bud.  Are you able to tell what type of food is best?  I have been using all purpose Miracle Gro.  Also, should I cut the bush down to just above ground level each spring, or should I leave it full grown and only prune dead branches?

I make compost tea – should I limit how much I add to my annual/perennial garden?  Should I pour it at the base of each plant or just spread it around the garden?

Answer:

The first question in regard to your rose bush to be addressed is if it is receiving sufficient light.  Roses do require 6 hours of full sunshine.  Another factor for your having no blooms is that too much nitrogen is being applied promoting lots of green growth.  It is always recommended to use fertilizer specifically formulated for roses.  If you like to use the Miracle Gro product, they do have a specific one as mentioned that has a high middle number, phosphorus which promotes bloom.  These are the numbers to look for, 18-24-16.  Also included in the product are specific micronutrients required for roses.  Rose fertilizer should be applied every 4 weeks beginning in early spring and ending at the end of July.

For the rose bush pruning:  only the dead branches should be pruned down to just above ground level.   If there are very long whip like branches in the autumn they should be pruned in half so that they would not be prone to being broken in the winter winds.

Compost Tea:  One would use compost tea the same way any liquid fertilizer would be used in the yard/garden.  Absorption through the foliage is the best way for the plant to receive this type of fertilizer.  Compost tea can be used regularly throughout the growing season from seedling through to die off.  Vegetables, perennials, annuals and perennial vegetables and fruits (asparagus, rhubarb, strawberries) can be fertilized every week without harm.  They will thrive on this treatment.  Compost tea may also be used as a liquid fertilizer for the lawn.   The ‘tea’ should be diluted to be a weak amber colour and be used within 6 hours of it being made.  The compost that was used to make it should go back onto the compost pile.

Question: Preparing Soil in a New Garden Oranic and Non-Organic

I started a new garden last year (I ripped out the sod from the front yard and filled with 4-way top soil) and it did not produce well at all.  This spring it has a lot of weeds and grass growing in it already.  I am wondering how best to get rid of the weeds before tilling and then what would be best to add to the garden to make it more fertile.

Answer:

Following are a few ideas for you involving what to do with your new garden.  The suggestions are involving both non-chemical and chemical solutions.

Here are the suggestions:

– depending what weeds they are, the majority could be controlled by tilling.  This would be the case if they are annual weeds.  Quite often when you buy 4-way mix these are annual weeds that are in it.  However the grass may have to be sprayed with Round-up beforehand.  A good solution would be to spray with Round-up for the grass and weeds, then add some well-rotted manure and work it in well with the tiller.  Also a soil test may indicate whether some fertilizer or amendment is required.
– 4-way mix composition is specific to the company from which you purchase the product.  Check back with them for an exact compostion % on all ingredients in the mix they sent to you.  Quite often there is insufficient organic material in it and too much dirty (weed seed infested) top soil.  It should probably have at least 35% well-rotted manure or other manure compost to be a good mix.  It should also include 40% sandy loam and 25% peat moss or partially composted leaf mulch.  To correct the soil this year you could hand dig all weeds first then add your choice of organic material and till.  You could also grow a legume crop to till in after the garden is finished and top dress again with compost or peat moss in the fall.  You may need to fertilize with a balanced 10-10-10 liquid application during the growing season.
– you can make an organic weedkiller using apple cider vinegar, salt and some Dawn (original) dish detergent.  You will probably need 2 applications depending on the weeds.  Then you should amend the soil with a bulk compost (ie. several yards to have about 2 inches on top) such as mushroom compost or bulk worm compost.  Reimer’s soils in Winnipeg sells mushroom compost by the bag or yard while Miracle Ranch on Garven Rd. in Birds Hill sells bulk worm compost.

A Note about Where to buy Organic Soil:

Bulk “organic” soil from a soil and landscape supplier would be questionable since they obtain most of their soils from farm land that is being developed into new housing subdivisions. Unless you know an organic farmer that would be willing to sell you a few bags of soil the only option is bagged soil. Some garden centres do carry “organic soil mixes” in bags but look for bags that say “certified” organic since sometimes organic simply means that it contains composted and natural ingredients. You could also mix up your own soil based on the square foot gardening method which is a combination of peat moss/ vermiculite/ and combined compost mix in a ratio of one third of each product. Each of these choices is expensive initially but once you have the base you will then maintain it by adding your compost and perhaps some additional bagged soil as needed. Since most bagged soil mixes do not contain actual “soil” you will have to use an organic fertilizer to provide some of the minerals and micro nutrients.

Question: How to transplant seedlings, bedding and container plants

I have had trouble getting bedding plants or container plants to transplant successfully. What is the best way to plant these plants without losing some of them?

Answer:

When buying bedding or individual starter plants, make sure that they are healthy to start. Look for strong stems, no yellow or black spotted leaves and the soil should be moist, but not soggy. Once you get the plants home, they should be hardened off by gradually leaving them outside, first in sheltered shade and then moving them into the environment where you intend to plant them. If the plants have already been exposed to outdoor conditions this is less necessary. If possible choose a cloudy, calm day to do your transplanting. Be sure to prepare the soil where you intend to plant so you have a loose loam soil. Water your plants a few hours before you intend to plant, then remove from their containers and check the roots. Quite often container grown plants are root bound so you need to loosen or “tease” the roots. Plant in the prepared spot, but do not bury deeper than where the ground level was on the stem in its pot. Press the soil firmly enough so that there is good contact, but not packed and water thoroughly. You could add a transplanting fertilizer (higher middle number) to your water. If you are planting flowering plants that are already blooming, pinch off the flowers. This is important even if it sounds cruel. You want the plant to put its efforts into settling into its new home and not try to maintain its flowers. Be sure to check on your transplants daily to make sure the soil is moist and that there hasn’t been any damage from wind, insects or other creatures. After a week or two they should be established and starting to show signs of new growth. Water, fertilize and enjoy.

Question: Colour Palette for Flower Garden

This question was from the ‘Gardening in the Heart’, ‘Chat with the Gardeners’ – Designing a Garden Naturally – Lisa Renner for John Harper
When designing flower gardens do you recommend a basic color palette that is repetitive to create unity throughout or do you suggest breaking up in sections.

Answer:
Color is great fun to work with but can get chaotic at times. And of course, flowering times can make things even more complicated. Imagine how many different plants you might need to keep a white garden in bloom all summer! I suggest developing a color palette that may shift seasonally, but you need not adhere slavishly to the palette. Contrasting colors add excitement to a flower garden.

In my own garden, the background colors (small trees, shrubs, vines, etc.) are primarily shades of green with a large red-purple component, mostly with shrubs such as different varieties of ninebark (Diabolo, Summer Wine, Centre Glow, Tiny Wine, etc. are all shades of purple). I enjoy both repeating these warm reddish hues as well as contrasting them with colors such as yellow-greens (Lemon Candy ninebark, Eldorado feather reed grass, and other yellow-foliaged plants, for example).

Once you have established a color palette for the background, you are free to explore numerous flowering possibilities in the middle ground and foreground. I sometimes use grey plants such as sage and white-flowering plants to soften harsh contrasts like pink and yellow. A number of types of sage (Genus Artemisia) do well in Winnipeg gardens (prairie sage, pasture sage, Silver Mound, etc.).

If you are planting a traditional English border, I suggest looking at Gertrude Jekyll’s drawings. If you are more interested in a wildflower meadow, try looking at pictures of Piet Oudolf’s gardens. I’ve taken the liberty of including a few photos from my own garden to illustrate some color combinations. These are in summer, so contain many warm colors. Spring is much cooler, with lots of purples and whites with accents in red, or other warm colors.
I hope this gives you some ideas. Happy gardening! -John Harper – Studio169 Landscape Architecture (studio169.ca)

Question: Best grow lights and containers for seed.

What are the best containers for starting vegetable seeds? Also I’d like info on best grow light system.

Answer:
Planting containers can be almost anything from recyclable containers, such as the ones that fresh mushrooms or salad greens are packaged in to wood fiber, peat, and reusable plastic grow sets. The most important thing to take into consideration is that the container has good drainage holes. The depth is also something to consider since some vegetables such as salad greens usually have shallow root systems so don’t need as deep a container as some others such as tomatoes or peppers. You may have to start your seeds in a shallow container first since seeds such as tomatoes, peppers and eggplant do much better if they are provided with bottom heat (from a garden heat mat, not on top of the fridge as some information sites still give that suggestion). Once the plants are larger, you would transplant into deeper containers. Peat pots or pellets, are sometimes difficult to control even moisture and they also tend to break down if plants are in them for a longer period of time. If you are going to reuse containers, be sure to thoroughly clean them. Use sterile starter mix soil to reduce the chance of disease problems.

Grow lights are very important since lack of proper light just results in weak plants. Currently, the most popular grow lights for the home gardener are the T5 full spectrum LED lights with a rating of 6400K. There are a number of brand names and they are quite readily available. They are more expensive than the older florescent lights, but if you are just beginning seed starting, the T5’s are a good investment. Also, you can add on to some of the combination kits if you want to at some point, which is an important feature. The important thing about growing under lights is that you need to keep your plants within 12 to 20 cm or 4 to 6 inches from the lights. This is another reason that the LED’s are good since they are cool and won’t scorch your seedlings.

Please check the How-to-video on the MMGA website about “Seed Starting” Click Here – even though the information is about starting flowers, some information applies to any plants. Remember to always check the seed packages regarding when to plant, how deep to plant and soil temperature. Try not to plant too early, since most vegetables, other than your hot peppers and some heritage tomatoes, should not be started before late March.

Question: Summer Fallowing

I am leaving my in-ground garden fallow this year to deal with the weeds. They’ve just become too much to deal with in the time I have available, so my plan is to summer fallow the garden much as we did with crops on the farm when I was a kid. In addition to that I am expanding the garden by putting in some raised beds, so we won’t be completely gardenless. I’ve got a garden tractor and some implements, so as long as there is no crop there, I can keep it tilled up. I’ve got questions though. I know summer fallowing is hard on the soil. I plan to keep adding leaves and compost as usual to keep as many nutrients as possible. It disturbs the worms and leads to erosion and all of that, but I don’t want to use chemicals and can’t keep up by hand weeding. Should I use a rototiller or a spring-tine cultivator? Should I alternate between the two? Should I keep watering with compost tea to keep the soil as active as possible? I do want as many weed seeds as possible to germinate so I can till them up, but would a monthly shot of compost tea make a difference? Would it be too much?
Should I add compost (leaf mold and manure) and top soil (4 way-mix) over the whole summer or just at the end of the year? Does it matter? The soil needs rejuvenation, and it’s easier for me to do a little at a time.

Answer:
Add a 6 to 8 inch layer of leaf mould and manure over the whole garden, not 4-way mix as this could contain weed seeds. Then cover the whole area with black plastic and leave it for the summer. Any active weeds would be killed by the heat generated under the black plastic and the worms that are in the soil would start to break down the manure and leaf mould. In the fall remove the plastic and till the whole lot under using a rototiller. Then add another layer of manure and leaf mould and leave this on over the winter. The following spring till this in then plant.

Compost tea is only really needed to provide extra nutrients for the plants that are growing.
For your raised beds you could make your own soil mixture following the Square-foot gardening method but first put landscape fabric under the beds to prevent the weeds coming through. Some 4-way mix is good and some contains a lot of weeds.

You could also put down a layer of wet newspaper (6 to 8 inches thick sprinkled with water to make them quite wet). Put the leaf mould and/or manure on top and still cover with black plastic. No point adding compost tea as it would feed the weeds.

Raised bed soil depends on how deep you want to make them. It is suggested to use three-way mix as four-way would settle too much. Keep any weeds down by putting down grass clippings between the rows and planting quite close together.

Square-foot gardening soil mix is blended compost, coarse vermiculite and peat moss.
The blended compost to use is sheep manure, cow/steer manure, worm castings, mushroom compost and generic-bagged black earth. You mix all of these together and then add the same amount of coarse vermiculite and peat moss by volume.
No weeds in this soil mix and it has all the nutrients , structure and water retention that plants need.

Question: Starting a Raised Organic Garden

I would like to start an raised organic vegetable garden. I have a garden bed already made. The perimeter, above ground, is about 6″ above ground and made of stone. My concern is leaching of contaminants (lawn fertilizer) from the surrounding backyard into the bed. Please advise how you think I should secure the bed to avoid this problem.
I like option 4 – raising the garden bed height above ground to 20″ total.

1. I would like to use the same/similar stone blocks to raise the height of the bed Do you envisage a problem with this, given my concern of cross contamination? Or, what type of “stone block” would you suggest.

2. What is the best soil recommendation for organic gardening?

Oakville, Ontario

Answer:
There are a few things to consider in order to address your concern.

1) First and foremost it is important to avoid the over fertilization of your lawn and in fact of any garden bed as this will prevent the loss of fertilizer through leaching and run off with surface water.

It is important to apply the right fertilizer ratio (right relationship of the macronutrients nitrogen, phosphorus and potassium; NPK percentage on the fertilizer label), at the right rate and at the right time. Please find more information on lawn fertilization and maintenance, including a seasonal lawn care calendar, in this OMAFRA (Ontario Ministry of Agriculture, Food and rural affairs) Fact Sheet http://omafra.gov.on.ca/english/crops/facts/08-017.htm

Leaching of fertilizer is the downward movement of plant nutrients, in particular nitrogen, with water beyond the root zone of the plants. This is of a concern as leached nitrogen eventually leads to the contamination of groundwater.

In urban environments the problem often stems from an over application of fertilizer on lawns and gardens. However, this leached fertilizer is not available to plant roots anymore. Practically one could say it is fertilizer going down the drain.

Of the other plant macronutrients excess application of phosphorus is known to lead to the contamination of surface water often via soil erosion. The loss of potassium, although it can occur in particular circumstances, seems to be of lesser significance.

2) If your lawn slopes towards the vegetable beds and water drains into the beds fertilizer could be washed in to the soil of the beds. If the beds sit at the same grade as your lawn this is a lot less likely to occur as water moves downward in the soil through the soil pores.

3) A soil test of your lawn would help you define how much phosphorus and potassium your lawn fertilizer should contain (see OMAFRA fact sheet). A soil test of your garden beds would assess the nutrient levels and organic matter content of their soil and inform you if there is an issue of high nutrient levels in the first place.

The following link provides a list of accredited soil testing laboratories in Ontario http://www.omafra.gov.on.ca/english/crops/resource/soillabs.htm We recommend contacting the lab before sending soil for testing as the lab personnel can advise you on proper sampling and the tests necessary to answer your questions, particularly if you were also concerned about other soil contaminants. Do also ask if the test will come with an interpretation of the results and recommendations.

4) Another option would be building up your raised beds higher than your current 6″ to about 12-20″ with a raised bed frame preferably of untreated wood and fill them with soil suitable for raised beds from a reliable source. This would move most of your vegetables’ roots out of your garden soil.

While stone is often mentioned as an option for building raised beds very little information can be found on on the safety, particularly of the use of manufactured stone building blocks. As the topic is also somewhat outside our expertise I would like to refer you to this recent article form the University of Maryland Extension which may give you some guidance.https://extension.umd.edu/resource/safety-materials-used-building-raised-beds

As to your question regarding the best soil for organic gardening: raised beds are typically filled with a mix of topsoil and compost and contain about 25-50% of organic matter ( e.g. compost, manure, finely shredded bark) by volume.

As the soil products offered vary from province to province and from company to company the best recommendation we can give you is to contact/visit your trusted nursery/soil company. They should be able to inform your about the provenience, the composition and organic matter content of their soils and if the soil has been tested for its nutrient content and contaminants. Ask these question especially if you consider a bulk delivery of soil which may be less costly depending on the size of your raised beds. If you buy bagged soil you should find most of this information on the label. Getting these questions answered should allow you to find a good soil to start your organic raised bed vegetable garden.

Try to stay away from mixes containing peat as peat is not a sustainable product and from the soilless potting mixes (they for the most part do not contain any soil and the organic matter in them decomposes and you will have to refill your beds with the product often).

More useful information in the following articles
https://extension.umd.edu/resource/soil-fill-raised-beds
https://gardenprofessors.com/?s=Raised+beds