Many Impressive Primulas Can Be Grown From Seed

One of my all-time favorite spring plants are the primulas. Not the kind you find on display in flower shops and greenhouses (nonhardy florist types) but the kind that are hardy and will do incredibly well in many East End gardens.

A few varieties are available as perennials in local garden centers, but if you really want to have your spring garden filled with these delights you may have to grow some from seed. It’s easy and inexpensive, and as my collection of close to 20 varieties will attest, they are great plants. There are hundreds of varieties you can grow from seed if you get smitten.

The primulas are loosely categorized into several groups but this grouping is not all inclusive. Allioni’s primrose is one of the earliest flowering that is mostly evergreen with a small cushion of oval, sticky leaves that are usually hidden by the flowers, and there are many, many flowers. The tubular blooms can be in shades of white, rose or mauve and usually have white centers. Allioni’s is a primula that is long lived and does well in an alpine garden setting.

Primula capitata is known as the round-headed primula or Himalayan primrose. It tends to be semi-evergreen out here and can bloom for up to a month in late spring. The blooms occur on erect stems that have a white cast with dark violet flowers at about 12 inches. Native to Tibet, it thrives in damp, shady areas and the flowers with the long stems make nice spring cuts.

Primula denticulata is known as the drumstick primula. It’s a dense plant with rounded flower heads in shades of lilac, purple, blue, pink or white on erect stems. It grows in clumps with lance-shaped leaves. Also a lover of light to moderately shaded damp areas, it’s native to the Himalayas.

Primula florindae is also known as the cowslip primula. This is the largest primula in the group and the most fragrant. It does well in a partly shaded damp area with flower stems as tall as 4 feet, and the flowers give off a honey scent. Flowering is from early to mid-summer, and it naturalizes well with dozens of stems from each plant.

Primula marginata is known as the silver-edged primula. It’s an evergreen that forms rosettes of silver leaves that have toothed edges so this one has some year-round appeal. It blooms in late winter/early spring with clusters of scented, funnel-shaped blue/lilac flowers that have a white heart. The flowers are borne on short stems.

Primula sieboldii, or the Sebold primula, is a true perennial (not evergreen) with slim stems and flowers of purple, crimson, pink or white. The plants are easily established in drifts and do not become invasive. It may be the hardiest of the primulas, and in the summer if it gets very hot the plants will go dormant. It is neglect tolerant once established. The flowers are great for cuts and have a long vase life with stems of 15 inches.

Primula vialii, or the orchid primrose, was widely sold and planted about a decade ago. It turned out to be one of the shorter-lived primulas in our gardens but if divided every three years or replanted it’s a sure eye catcher. I’d seen pictures of Primula vialii several times, and it was offered by most of the mail-order nurseries. But after two tries and two failures I gave up. The plant isn’t even in my database so this must have been 25 years ago or longer. Maybe it’s time to try it again. It’s commonly referred to as the “poker” primula, and a few varieties even look a bit like a Kniphofia. This one, like many of the primulas, may be a short-lived perennial but is easily grown from seed. It thrives in damp, shady spots including bogs and near ponds.

Other varieties that might work well are the border and alpine Auriculas. These are among the most vigorous primulas and are evergreen and diverse in size and can be found in a wide range of colors. Blooming for up to three months and occasionally reblooming in the fall, they look great in groups, along paths or in borders.

There is also a Candelabra group, which some see as the most majestic in the family as they have eye-catching flowers atop tall stems. This is a long-flowering group from late spring right into the summer, and they are self sowing. Best planted in bogs, near ponds or in damp shaded locations.

A few of the hardy primulas may be short lived, and you should only expect to get two to three years of blooms from some varieties. The good news is that on a warm and cloudy late spring day many of these plants can be easily divided (after blooming) and will begin to flower again the following spring. One mature plant can often give you three divisions, but it’s variety dependent. You can probably even get away with early fall divisions, but these may take an extra year to flower, though most don’t.

I felt stupid when I began growing primulas because I’d seen them sold as indoor plants (the greenhouse nonhardy types) but never came across them as hardy garden plants until I found a few at a Southampton garden center. That was until I met Primula japonica “Miller’s Crimson.” I was on a wetlands commission site visit when, turning a corner around a border shaded by tall pine trees, I was confronted by what I can only call a drift of plants blooming in a true crimson red atop foot-tall stems that just blew me away. I now have my own drifts of Miller’s Crimson, and each and every year they add their accent to the shady area. Mine begin to bloom mid-May and often continue into June, but inland away from the cool ocean waters they may bloom in late April. Seed of Miller’s Crimson sown in February can be transplanted to pots or cells in May then planted out in the garden in late August or September.

Miller’s Crimson comes true from seed and will self-seed as well. The plants that do develop from seed in the garden can easily be transplanted in the spring or fall or just rogued out if they are too plentiful. They fall into the class of “candelabra” primulas, and you need to keep an eye on them as they will establish as large “drifts” of plants and in some areas they can be somewhat invasive. There is also a white variety of P. japonica, but it’s not nearly as striking as Millers.

After my success with P. japonica I moved on to other species. I was in a photography chat room when someone posted a photograph of a primula that really caught my attention. I contacted the photographer who said he had no idea what the name of the plant was but that he’d photographed it at a botanical garden in Vancouver.

The picture got stuck in my garden brain, and while it took me several months to find out what it was, I did. This variety was Primula elator “Gold Laced.” It’s now established in one of my high-shade gardens and has been a reliable performer for eight years where it grows among the Cyclamen coum.

Primula vulgaris “zebra blue” has also been a stunner. This one teases me though. While it’s reliably hardy I only have two plants and so far (eight years later) it has not produced seed for me.

I don’t have a bog, a pond or a stream, but I’ve got wet spots and have found that my primulas do well in the high shade of my old and tall maples. The soil is fast draining so I add compost for water retention and just allow the leaves from the maples to drop in the fall giving the plants a light winter mulch. In the summer if we get dry I’ll water them deeply but I don’t obsess over it.

You can find a few varieties of Primula at local garden centers (make sure they are from the outside displays and not the indoor greenhouses) and Edelweiss has several varieties you can order online (edelweissperennials.com). Seeds of over 40 varieties are available from jellito.com. You can also get seeds from the Royal Horticultural Society (if you’re a member) and the Hardy Plant Society in the United States through their seed exchanges.

If you can only find the variety you want in a mix of colors but find you like one particular color and not all of them, just isolate that one plant from the others and divide it every year. I did this with a variety that the White Flower Farm offered several years ago that was Primula denticulate “blue shades.” Well, there was only one shade of their blue that I liked so I divided that one every year and now I have a small drift of blues that are identical clones.

Another variety that I’ve found easy to grow and reliable is P. kisoana, or the Japanese primrose. This came from Edelweiss in 2018. It naturalizes really well and is growing in an area of about 20 square feet at the base of a 150 foot maple. The flowers are a light pink and the foliage rounded with scalloped edges. There’s lots of good humus there, but once or twice in the dog days of summer I water the area well if I see them wilting.

If you need instructions on growing these plants from seed just drop me a line and give the Primulas a try. I think you’ll be delighted. Keep growing.

It’s looking like the forecast for cold and wet at the end of February may be pushed into mid-March. The experts are now thinking the polar vortex will be acting up a bit later and pushing into Europe then later a bit into the Northeast. This could mean a cooler, later and wetter spring. One way to plan and hedge your bets will be to seed indoors a bit later and plant outdoors a little bit later. It also means you may want to have row cover material like Reemay handy to protect from any ice or snow on early crops like greens and peas.

On the other hand, the red-winged black birds and the grackles showed up two weeks early this year. I confirmed this with other birders in the area who noticed the same thing. Apparently, the birds are watching a different weather forecast.

Speaking of weather, one of the weather stations in my trials has had an issue. The Ambient KestrelMet 6000, the most expensive of the group, lost power during our deep freeze and stopped reporting. The problem was ice buildup on the solar panel resulting in loss of power. This station needs more power than any of the others as it’s larger and has an aspirated thermometer, one with a fan constantly moving outside air over the sensor. Each of the other four stations in the trial has solar panels and this is the only one that had an ice buildup issue. The less expensive and smaller WS 5000 from Ambient did not have this issue and the data from the soil probe is pretty interesting. The soil three inches down with three to five inches of snow on the ground never got below 30 degrees and only for two days.

You may see online vendors offering annuals and vegetables and perennials as “plugs.” It’s really a misnomer from what we once though of as plugs (about the size of a thimble) as these new “plugs” are about 1.5 inches wide and 3 inches deep. Just consider them to be plastic cells just like you see on the garden center benches as four, six and eight packs. The ones I noticed were for annuals used in cutting gardens. They were about $6 per plug but — and this is a big but — these were varieties that you rarely find in garden centers so an economical and easy way to plan and plant a cutting garden (Select Seeds). Otherwise, no bargain.