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Growing in the Green: Trials 2010: our Top 10 list

November 23, 2010  By Melhem Sawaya

Due to this year’s nice and warm summer days, the heat-loving varieties,
in particular, gave visitors to the Sawaya Tenth Annual Garden Trials a
very rewarding show

Due to this year’s nice and warm summer days, the heat-loving varieties, in particular, gave visitors to the Sawaya Tenth Annual Garden Trials a very rewarding show. Umbrellas were used to keep the hot sun off, not any rain.

Though there were still many rainy nights, most of the days, fortunately, were still sunny and warm. It is amazing how fast the recovery is for some plants, and how there is virtually no setback for them at all, while others look like they went through the heavy-duty cycle in the washing machine. These weaker ones take five to seven days to recover, mainly because of shattered flowers and Botrytis getting a hold of the rest of them.


The main purpose of our trials is to see the varieties that perform best in our climate (southwestern Ontario). For the past 10 years, we have seen some genera that perform especially well and others that have struggled. Calibrachoa production, for example, has increased by over 1,000-fold over the past few years, not only in Ontario, but across Canada. This dramatic increase is due to its great garden performance, and the excellent show it puts on from early spring to late fall as long as we are able to fertilize on a regular basis with every watering.

In my personal experience, ivy geranium in Ontario is a total loss as a garden performer. We see that hardly any of the regular types were produced this year, while the interspecific varieties, such as ‘Caliente’ and balcony types, have been on the increase. After all, we are growing plants for the ultimate consumer, and their success is our success!

■ All trial plants are donated and sold by Norfolk General Hospital volunteers right from the trial gardens site. The people who come are amazed by the quality of the plants, and are happy to pay $20 a pot for annuals, even on Aug. 20. So why are gardeners not getting the full potential beauty out of their plants?

The answer is simple: we are not communicating the information effectively to the ultimate consumer. Unless we are planning to shrink our sales by 2.5 per cent every year, we better get together with our buyers (stores and garden centres) and educate the consumer. This is in addition to doing our homework in selecting the best garden varieties.

In all businesses, mistakes and omissions are costly. Therefore, it’s important that all of us plan carefully for the right outcome.

Here are some suggestions on how to increase sales:

  • Only grow garden-proven varieties.
  • Sell the plants in larger containers than you are used to growing them, i.e., flats material in much larger cells or 4” pots, and 4” material in 6” pots. The rule of thumb is that if you have to apply growth regulators more than once to ensure the plant fits within the container, then the container is probably too small for the plant. Examples include dahlia, blue salvia, Profusion zinnias and gazinnia, to mention a few.
  • Plant in a good potting media and avoid weird additives. Extending the plant 12 hours or a day before watering creates a false expectation for the consumer.
  • Top-dressing containers with slow-release fertilizer could be a setback for varieties that cannot take a heavy dose of fertilizer all at once, and that will happen once we get high temperatures because slow-release fertilizers are released based on temperature.


  • Provide liquid fertilizer free, as a bonus, when they buy your plants. Mix it in 200-litre barrels in concentrated levels so that consumers can dilute it 1,000 times to end up with a fertilizer in the range of 150 ppm.
  • If we don’t do anything else, we must sell simplified drip kits so the homeowner can water his or her plants effectively and regularly. By doing this, I guarantee plant sales will increase three to four per cent rather than decrease by two to three per cent each year. People who visit our trials ask about our drip system and I tell them where to buy it and the simple steps needed to put it together. Those who do install it make it a point to come back and thank me for the hint. They also tell me how they are going to buy many more plants because they know the plants are going to do very well without any more work.
  • Get involved in advertising plants and their benefits. In this industry, there is no sitting on the fence. If we are not part of the solution, we are part of the problem.
  • It was very hard to pick some highlights from the 2,200 cultivars onsite, and it is much harder to pick the Top 10. Here are the criteria:
  • The cultivar has to look good from June to frost.
  • Minimal deadheading.
  • Will recover from heavy rain storms in a short time.
  • Will take hot weather or will actually perform better with high temperatures.
  • No diseases such as Botrytis or powdery mildew.
  • The plants have to have customer appeal.
  • Some of the cultivars that made our Top 10 list are not used as much as others more popular in the market because:
  • The breeder has a weak marketing program.
  • The breeder does not appreciate the potential of the specific cultivar.
  • The cultivar does not qualify for any royalties, so it is put on the back burner.
  • A lack of cuttings.
  • Supplier crop failure or inconsistent delivery of a quality product.
  • The source of the cuttings doesn’t have the proper shipping connection.
  • Consumers are not aware of the cultivar’s excellent performance.

■ Here are the Top 10 cultivars, starting with Number 10 and continuing to the champion performer.

Scoparia ‘Illumina Lemon Mist’ (10) is one of those varieties that have excellent performance but are not popular because there is no marketing behind them. Try it in large containers, hanging baskets and in the right combination. ‘Lemon Mist’ flowers the whole summer long without deadheading. The bonus is that it has hundreds of yellow flowers.

Gaillardia ‘Gallo Dark Bicolour’ (9) is a perennial that puts on a great show of “annual” flowers. It flowers the entire summer and the blooms last for a long time, so deadheading is not much of an issue. ‘Gallo’ is excellent in landscape or large containers or on its own. There is no reason it can’t be put in mixed containers.

Dipladenia ‘Summer Bell Velvet Red’ (8) is one Dipladenia that is growing in popularity more and more as we learn how to produce them effectively with good quality and at a reasonable price. Dipladenias should be grown in large pots or in landscape.

Gaura ‘Stratosphere White’ (7) is one of those plants that gets better looking with age. The larger it gets, the better the show it puts on. Our problem is that we grow gaura in 4” pots that just don’t do it any justice. Grow it in large pots (12-14”), and let it fully show its beauty and durability. Mix the gaura ‘Stratosphere’ with begonia ‘Dragon Wing’ and you have a winning combination of superior garden performance and excellent show.

Begonia ‘Dragon Wing’ (6) is the top garden performer. The main reason it is not even more popular with consumers is that we sell it in 4” or maximum 6” pot size. The consumer never sees its potential! Grow it alone in large containers or display a large specimen near the 4” or 6” containers … or at least display a very large picture of ‘Dragon Wing’ in a landscape.


■ Begonia ‘Solenia Orange’ (5) is one colour in this popular series. All the ‘Solenias’ feature excellent garden performance, much like the other Rieger begonias. All of the Riegers are excellent for hanging baskets and landscapes. In the past two years in our trials, the Riegers showed excellent performance; I’ve also seen some amazing landscapes that looked great from May to frost.

Scaevola is one of the first genera that started the vegetative garden plant explosion; however, for the last few years, its use has slowed down, even thought scaevola garden performance is second to none. The reason could be that growers don’t use it enough, either due to lack of production knowledge, or because of the few extra production weeks needed to produce a quality hanging basket. ‘Blue Falls’ (4) is one of the better performing in our trials compared to other scaevola.

Mecardonia ‘Gold Dust Yellow’ (3) is another of those varieties that is under-used; growers are missing the boat by not offering this variety. It is a compact trailing variety, loaded with yellow flowers. ‘Gold Dust’ is excellent for rock gardens, large pots combined with the right combinations, and landscapes.

‘Soleil Purple’ (2), in my opinion, is the best garden performing petunia. It flowers the whole summer long, rain does not hinder its performance, sunny and warm days make it even nicer, and you will never see a yellow leaf all season. The only reason it is not the champion is because we do not know the performance in greenhouse production. Try some Soleil; I would appreciate some feedback!

The Supertunia ‘Vista Series’ (1) is the champion variety for the 2010 Sawaya Garden trials. Name a characteristic you like in a superior variety, and the Vista series has it. It flowers the whole summer, rain has no negative effect, hot weather is welcomed, Botrytis is never seen on the plant or the flowers, and it has vigorous and dense growth. It is a winner in all aspects!

Next year’s Sawaya Garden Trials open house is July 20. Mark your calendars now and all are welcome!

Melhem Sawaya of Focus Greenhouse Management is a consultant and research coordinator to the horticultural industry. Comments on this or any other article are always welcome; please e-mail, or visit or .

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