May 19, 2020

Springing Forth Against All Odds: Rare Annuals, and A Garden Update

My new border garden is about 60% complete, but like all good garden designs, development takes time. This urn is temporary until I find the right (and affordable) object to center the design, and the walks still need to be set in (gravel, peastone and cobblestones) but even incomplete, it's already looking nice.

In the kitchen garden, straw lines paths as onion seedlings interplanted with plugs of mesclun start the season off with quick growing greens reducing trips to the supermarket.

Mesclun washed, and chilled is crispy and tender when it is fresh and home-grown. I've been sowing one plug tray every week, setting out the plugs 8 inches apart after three weeks which allows just a pinch of seed to mature with enough space and light.

This time of year while it is still cold at night and cool during the day, tropical plants that will become large specimen plants outdoors in the summer are being potted up. I like to mix unusual plants with more common ones, always planting single species in each pot rather than mixed containers which have become so popular. This Iochroma is a nightshade shrub with brilliant violet tubular trumpets in clusters from mid-summer through autumn. A cutting planted now will grow quickly.

This is a typical discovery in the greenhouse this time of year - black walnut seedlings that squirrels sneak into pots every autumn. It's amazing to see how well they hide them! I found this one in a begonia while I was pinching back all of the red snapdragons.

If you look back in the blog about ten years, you'll see my obsession with an obscure bulb (corm) from South Africa called Rhodohypoxis. I traded many cultivars and crosses with friends years ago, but then lost all of my collection to mice one winter while they were dormant. A few months ago while shopping for some new varieties I came across this one named 'Matt's White' sold at Far Reaches Farm. Apparently a friend shared a number of my selections with them years ago, and this while one was chosen for it's short growth. It may be a named cultivar but since that provenance is questionable, they named it for me! (for now). Maybe someone will be able to ID it soon.

My new book Mastering the Art of Flower Gardening was published in March, and while my speaking tour has been cancelled or postponed indefinately, you may find it useful for some of your flower gardening projects. This chapter on annual poppies, for example, is one that seems to be popular and useful for those interested in alternative ways to raise the pretty and tender annual poppies.

You may remember my experiments with sowing the annual poppy P. somniferum 'Lauren's Grape', which is so popular with many serious gardeners but impossible to find at garden centers, and truly a species best sown direct in late winter. I wanted to test alternative ways to raise these often challenging poppies. My early discoveries reinforced that the seed germinates best at 70° F, in a greenhouse or under bright lights, but then what does one do? Here are my results.

Now, three months later my single-sown seedlings that were once so tiny in their 4 inch pots, have grown into lush rosettes. Slower than a few friends of mine who were growing them as well in Vermont, I was able to alleviate their growth rate by raising the nighttime temperatures from 40° F  to 65° F. In two weeks in late April, they doubled in size. In early May I relocated to to a cold frame outdoors to harden off.

Annual poppy seedling being hardened off in one of my cold-frames. Here you can see  P. somniferum, P. rhoeas (Shirley Poppy), Viscaria, salpiglossis and in the back, about 30 Cerinthe major 'Kiwi Blue' - the Blue Honeywort.

My basal stem cuttings taken from early-emerging delphinium in March are now rooted and able to be potted-up. Still in the greenhouse, the root now are growing quickly. This method, rather old-fashioned, I discovered in an old gardening book from England. Cut from established clumps just as they are emerging, the cuttings (cut deep underground) are set into sand or perlite, in a clay pot set in a tray of water.

My snapdragon seedlings are always a special project as I adore healthy, strong, tall and bushy snapdragons, and finding well grown or properly grown snaps at a garden center is difficult today as most are either treated with growth regulators or are sold in-bloom. These seedlings takes time, and I can fuss with them more at home. Seedlings are set into 4 inch long-tom pots, pinched and their fertility adjusted (with Cal-Mag or high potassium) food which they appreciate. Pinched twice (at least) these will be set in large groups out into the borders for a spectacular summer show.

These are pinched tips from another set of snapdragons. I used to not pinch snaps, as I wanted to tall, florist-style snapdragons, but those are impractical outdoors as they will tumble without netting and one ends up with bent stems. Yet, if one pinches early and frequently (at the second pair of leaf stage) a sturdy enough plant can be achieved that will still produce relatively long stems.

Cerinthe major var. purpurescens 'Kiwi Blue' is a secret fav of many garden designers. Also rarely found at garden centers, the large seeds are not only easy to sow, they grow quickly (sometimes too quickly). I usually sow mine too early (I never learn), but again, with pinching, the plants branch and by the end of May, a plant in a 4 inch pot is already an impressive size. Set out into the border in great numbers (as all annuals should be planted - in groups of 20 or 30) the show is nothing but sensational.

New for me this year is this: Silene pendula 'Sibella Carmine', a new introduction from Fleroselect that promises to produce a cloud of magenta flowers. It's reccomended for hanging baskets, but I am going to try bedding it out. I am very excited by they dense growing habit already.

By far a favorite annual last year in my garden is this: Phacelia campanularia. These are just beginning to bloom in a pot but last June they put on a sensational show out in the border. A Californian native wildflower, these are certainly something you will need to grow from seed early indoors, but I think that they are so worth the effort. I'll let you know how they do in a container, but I also set out about 25 plants in the border and a few in a clients garden.

Im not growing as many sweet peas this year as in past, but I do have three areas where am growing them, each one demonstrating three different methods. This structure shows my cordon method - the traditional and fussy way exhibitors grow their sweet peas for the sweet pea shows in England. Pinched plants are them restricted to a single stem, which is tied to a single bamboo cane which results in very long stems and flowers that are almost double the size of traditionally grown sweet peas.

In the background here you can see one of my tee pee's. Constructed on a base on 8 foot bamboo poles, branches and twigs are then tied onto the structure. Sweet pea seedlings that were started early in deep trays were set in around the base, pinched back to produce the stronger stems and by July this structure will be covered with flowers. These will be a mix of dark purple, violet and blue colors.

The last method is new for me - the 1910 dwarf variety 'Cupid Pink', from seed raised in the UK as most American strains are considered to be inferior to the original heirloom - I tried these last year along with some 'Knee Hi' varieties from the 1970's in pots for a wedding in Vermont, and they were a hit. So I am dedicating one of my windowboxes to them just to see what happens.

I terrible iPhone shot, I know, but this angle does show how I am setting out these cool-weather annuals out in the border - between the tulps. Upper left are some salpiglossis, lower right a few Phacelia and in the center-right, Viscaria occulata.

I thought i would share a photo of one of my clients gardens last year in suburban Boston using a selection of hard-to-find annuals raised from seed. 

It's Memorial Day weekend here in the US which in my growing zone (5b) is traditionally the time one would plant out tomatoes and basil. It's been too cold this year, as it was last year, as night temps are still in the 40° s so no need to rush. My basil seedlings are just forming their first pair of leaves - the time to transplant into larger pots (I'm reusing some 6 packs from pansies). Im growing a number of varieties of Basil including the traditional variety used for Pesto (Genovese) but it will succumb to BPM Basil Powery Mildew by high summer - a new disease introduced 10 years ago.So I am also growing a few of the newer disease resistant varieties like Prospero. Im curious to see if I can taste the difference as these new resistant varieties are crossed with other basil varieties like the Asian basils or Cinnamon basil's. The flavor profiles are very close though, to the true Genovese, but stay tuned.

Aside from unusual annuals and vegetables, the plant geek in me can't help but grow some true rarities or uncommon plants. These pots are from seeds acquired from the NARGS (North American ROCK GARDEN SOCIETY) annual seed exchange. Some Asian delphinium species and other alpine gems - I'm thrilled that the germination is so good this year. these have been outdoors and snowed on since late February.

The entrance to my house shows a display of pansies and violas. I prefer to pot three plants to a pot and not to jam in many plants which is so common today. Three plants pinched, and tended to daily to remove spent blossoms and seed pods will fill out a pot in just a few weeks. You'll be shocked at how large they will get, and I prefer the look of a single variety per pot or basket - a more horticultural look, and the effect is more 'Great Dixter' than  'spiller, thriller and filler'. I'm kind of over that look.

 I just had to share this lilac that I planted two years ago. I lost the tag so I don't know what variety it is, but it's magnificent, with a color so intense.

Baby chicks are hatching every week. These guys are all from the green eggs laid by the Aricana hens, but clearly our black Australop rooster has been busy with the hens. They are so cute!

A friend of ours gave us 6 eggs from their Royal Palm turkeys, but we had doubts about them hatching in our incubater, so Joe ordered 15 rare breed turkeys that will arrive in June. Of course, all 6 hatched and are healthy, and growing quickly. I found two of them escaped and perched on the kitchen counter a few days ago. No paper towels, so we are re-purposing emails for their bedding!

Lastly, I never announced it but I was honored to have been asked to feature our garden on a Garden Conservancy Open Days tour (you know how I freak out about tours! but this was a big deal). I was also offering a Digging Deeper program on June 6h but sadly the tour and program has been cancelled or postponed until next June. It does give us time to get things in order around here (hey - it's a mess!) but I promise that it will be even better next year!


  1. congrats on the cute babies and postponed garden tour. Your greenhouse and garden are a-may-zing! Photos and info v. inspirational/aspirational!!

  2. Excellent article and great pictures!
    Love to read all. I'll spend more time to reading the older posts too!!

  3. The lilac variety reminds me of 'Monge'.


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