Not so much an official trial, as an effort to grow out each of our sweet peas for comparative study. We grew out fifteen varieties among the other flowers and vegetables at our Kirkland House demonstration garden here in Ladner this year, creating one of the most fragrant garden experiences of all time.

The sweet pea plant (almost all cultivated varieties are Lathyrus odoratus) originated in Sicily and the nearby surrounding Mediterranean region. They have been cultivated since the 1600s, and some of the oldest strains are still around. But every year new varieties and combinations are introduced, so a gardener with obsessive tendencies could easily spend a lifetime studying and breeding them.

Like other flower types, they are judged on a number of criteria. The intensity of fragrance varies from one type to another. At the time we planted, we were out of the infamous High Scent, which must surely be the most fragrant of all. I have grown it at Kirkland in previous years, and it always receives comment from visitors.

Sweet peas are prized as cut flowers because they remain fragrant for several days after cutting, and this can be enjoyed indoors. So many of the varieties are judged by the length of their stems and number of flowers per stem. Height and vigour are other desirable characteristics.

Finally, colour combinations have a huge impact, from the subdued Spring Pastels to the brilliant Royal Family and Cutherbertson blends. I personally prefer some of the single flowering types like the all-white Royal Wedding, or the bicoloured Painted Ladies. I also like the deep, rich blues and purples in the Bijou Blend.

Although we have been gardening at Kirkland House for eight seasons now, this was the first time we have had very heavy pressure from aphids. I would guess that our mild weather last winter (and climate change in general) may have played a role in this. But it could be that greater numbers of them were more obvious because we had so many sweet peas this season. Only the sweet pea Janet Scott became infested, first with green aphids, then with black ones. We decided to uproot and remove the whole row about mid-July as it was becoming an eyesore. Typically in this garden we rely on Companion Planting with Umbelifers to bring in the predatory insects that control aphids and other pests. This is the first year the aphids managed to overtake our beneficial insect population. Now in August the second generation of ladybird beetle larvae have hatched, and they are everywhere in the garden. Hopefully this will knock the aphids back a bit.

Various other sweet peas responded to the heat of high summer by drying and withering. Early Multiflora, Painted Ladies, and Spring Pastels were the first to pass their prime, but each after a spectacular display. Royal Family, Mammoth, Cutherbertson, Bijou, and Old Spice are still going strong in early August. We are taking regular cuttings and doing what we can to remove any seed pods. Both of these keep the plants producing more flowers. Cutherbertson has grown absurdly tall, and is using the eight-foot-tall Solar Power sunflowers as a trellis. We can no longer reach the highest flowers!

For trellises this year we used very basic bamboo canes, intertwined and tied with the always reliable Knotty Garden Twine. Beyond the addition of compost and Glacial Rock Dust to the beds, we did not add any specific fertilizer to the sweet pea rows, and they all performed well. Here are some more specific thoughts:

Spencer Ripple Formula Sweet Peas
Spencer Ripple Formula (FL3204) features a pleasant mid range of colours with some variegated petals (hence the “ripple”), on quite vigorous vines that grow to about eight feet tall. The stems are long, slender, and quite rigid, so it’s a fine choice for cut flowers. Notice that there are several flowers per stem. The fragrance is intense – I’d say 8/10.

Patio Mix Sweet Pea Seeds
Patio Mix (FL3205) is a truly dwarf sweet pea intended for containers and flower boxes. It was so dwarf that it looked a little strange among the tall trellises of its cousins. Ours grew to about eight inches tall and then began to flop over, so it’s a good idea to provide some support with twigs tucked into the soil. The flowers are held relatively close to the plants, so they don’t work for cut flowers, but they come in vivid colours with mild fragrance. I think 4/10 on the perfume scale. This would be a very nice choice for window boxes – the scent is subdued but pleasant. This variety was pretty much finished by late July.

Striped Butterfly Blend Sweet Peas
Butterfly Blend (FL3279) was bred from Unwin’s Striped Butterfly Blend, and older variety from the UK. The flowers shown were cut later in the season, and the biclour Matucana-like purple/maroon flowers were more abundant at that time. Earlier in the summer there were more variegated flowers, but all of them grew on long stems with medium fragrance that makes itself known without being overbearing. My rating would be 6/10 for scent. The plants grew to about six feet tall on the trellis. I am a fan of the rich, darker colours on this variety, and I like that the flowers appear in tidy pairs on the stem. As long as we kept them cut, more flowers would appear.

Old Spice Sweet Pea Seeds
Old Spice (FL3280) is one of the workhorses among sweet peas. It kind of has everything for everyone. Six foot tall vines produce large flowers on long stems in a pleasing range from pure white to deep maroon and navy blue. The fragrance is strong (8/10 in my opinion), and the plants are resistant to hot weather and soil, so they continue to bloom through August. The growth is a tiny bit less tidy, with some sprawling happening late in the season, but that could have been my undisciplined trellis methods. Old Spice is good for cut flowers, and I think it would make an excellent screen on the right trellis, to break up garden spaces.

Royal Family Sweet Pea Blend
Royal Family Sweet Peas (FL3281) do a superb job. The flowers appear in pure colours — largely white, but with highly contrasting shades of bright red, deep maroon, and hot pink. There are some lilac and mauve flowers included. The vines grow to about five feet tall, with long stems, large flowers, and mild fragrance I would rate about 5/10. Flower production on this variety seems to accelerate in hot weather, and it continues to flourish well into August in my plot. We also carry Royal Family Certified Organic (FL3202) seeds.

Cuthbertson Sweet Pea Seeds
Cuthbertson Mix (FL3283) is at the opposite extreme to Spring Pastels, but it’s one of my personal favourites. The colours are anything but subdued, but the overall look is on the rich purple, blue, and maroon end. These are complemented by some pink and white blooms, but purple is the dominant colour in this mix, with many bicoloured “Matucana” type blooms. The vines appear to grow indefinitely, approaching eight feet tall now in early August. The stems are luxuriously long for cut flower use, and the fragrance is intense at about 9/10 in my opinion. This is like a sweet pea on steroids, and I would love to try it on a much higher trellis, or up the side of a house.

Mammoth Sweet Pea Seeds
Mammoth Blend (FL3284)
is named for its extra large flowers. Its stems are long and thick, making it one of the best for cut flowers, and it grows to just over six feet tall, requiring a trellis. The flowers appear from late spring right through summer in a pleasing range from white to navy blue, and it looks stunning planted in a long row. It’s like a wall of flowers. I would rate the fragrance as medium strong (say… 6/10), but the real feature of this variety is its suitability as cut flowers. This is the florist’s sweet pea. It has been a pleasure handing out bundles of these flowers in the garden and at our retail shop in Ladner.

Late Spencer Sweet Peas
Late Spencer Blend (FL3285) has been, along with Mammoth and Cuthbertson, one of the show stoppers from this trial. Planted in a long row in the center of nine raised beds, it has bloomed from May right into August, and shows no sign of slowing down. The flowers are large, borne on long, sturdy stems, and the fragrance is powerful at around 8/10 on my unofficial scale. The vines are about five feet tall, but the flowers are exceptional. They show much more variation between upper and lower petals, with the so-called picotee edging around each one. The colours are somewhat neutral — it’s very much a sweet pea, but it’s not distracting in the garden. We have enjoyed this as a cut flower, but it will definitely stink up a room with its heady, sweet scent. This would be a bit much for some people.

Painted Ladies Sweet Peas
Painted Ladies (FL3292) were the earliest of all our trial peas to bloom this season. This is a very old heirloom variety that has been around since the 1730s. Its flowers are petite and mildly scented, and each one is pink on top with a white skirt. For me the appeal of this sweet pea is its overall delicate look… Words come to mind like “charming” and “dainty.” These are not words that typically speak to me, and pink is not my personal favourite colour in the garden. Yet there is something of a natural appearance to this variety, as though this is what sweet peas were meant to look like. The vines grow to about five feet tall, but they sprawl more than the others. The stems are relatively slender, but long enough for cut flowers. I rate the fragrance low at about 4/10. This sweet pea wants careful placement in the garden. In the right spot it would have an air of antiquity and class.

Bijou Blend Sweet Peas
Bijou Blend (FL3294) remains my personal favourite among so many other fine sweet peas. Its rich colour range is dominated by blues and purples, but accented by the occasional highlight of scarlet or pure white. The stems are long, sturdy and uncommonly straight for excellent cut flowers. The vines are not huge at five feet tall, but larger than I described them in our 2016 catalogue [editor’s note to himself!]. We have them on a trellis growing quite upright, and they are still very much in bloom in early August. I would rate the fragrance at medium-strong (6/10), but as cut flowers, to my taste, they are among the best.

Early Multiflora Swet Peas
Early Multiflora (FL3296) does exactly what its name suggests. The long vines bloom early, with multiple flowers per stem. The stems are particularly sturdy, with good height for cut flowers, and the scent is mild (3/10), which will be a relief to some growers I know. The flowers are large and vividly coloured, but within a relatively neutral range of hues. This variety had past its prime in late July, but it is said that it can be planted again in the fall for winter blooms, which is something I plan on experimenting with in September. Sow as early as the ground can be worked in spring for a real show of spring and early summer colours.

Supersnoop Sweet Pea Seeds
Supersnoop (FL3298) is bushy and compact, and our planting was largely dominated by bright red flowers. Its compactness results in the flowers almost competing for space, so many of the stems are curved and short, jutting out wherever they can from the plants. This does not lend them well for cut flowers, but the variety would be ideal for growing in containers like half barrels. This plant is definitely taller than Patio Mix, but did not grow more than three feet tall. The trellis we provided was largely wasted. The appeal for me is the intensity and surprising range of the large red flowers. These appear in scarlet, cerise, magenta, and blood red, along with some dark purple and light pink accents. We pulled the finished plants out at the end of July to make space for our sprawling cantaloupes. But I would definitely recommend Supersnoop for smaller garden spaces where a flash of colour is needed.