Enticing Drosera hamiltonii To Flower

Barry Rice

Keywords: cultivation: Drosera hamiltonii

I am a connoisseur of mucilage. Why, I do not know, but those glistening jewel-like beads on Drosera mesmerize me. I have high standards for mucus---the gooey balls on D. regia are too large for my tastes, those on D. petiolaris too small. D. binata var. dichotoma puts on a fine show, but its variously-sized droplets alarm me. But when you are talking about the glittering adhesive dew drops on D. prolifera, D. burmanni, or D. rotundifolia--that’s the right track!

The problem with Drosera hamiltonii is in its glands! Most of the year its glandular tentacles are ratty and miserable, like a mangy dog fresh from an ocean bath. Still, I love to grow it. It has those flowers....

This sundew is fairly sturdy, and can be grown a number of ways. It does not care too much about soil mix, there are no secret formulae---it grows well in sand and peat combinations, pure milled Sphagnum (my favorite), or live Sphagnum. It has long ropy roots but I do not accommodate them with a deep container. Instead I use a shallow pot only 6 cm (2.5 inches) deep and let its roots coil in the bottom. I give it full sun in a greenhouse or a bright position in a terrarium (my brightest terraria have six fluorescent bulbs over them). I use purified water, and keep the plant continuously moist. I have tried fertilizing them with Miracid (foliar application, once per week following the concentration instructions given on the label), but the plants neither benefited nor suffered from this treatment.

A mature rosette of D. hamiltonii is approximately 6 cm (2.5 inches) in diameter. Its leaves hug the ground closely and are remarkable for how, as they grow, they unfurl like a carpet being rolled out (for example, see the photograph in Allen Lowrie’s Carnivorous Plants of Australia, Volume 2).

Drosera growers know that the way to look into a sundew’s health is through its mucous glands (ah yes, the mucilage---my favorite part). Transplant even an indestructible D. spatulata too violently and it complains with leaves bereft of viscous slime. What grower of D. prolifera does not stop dead in his tracks at the sight of undewy leaves? But with Drosera hamiltonii, you must squelch your anxieties and press ahead with your horticulture bravely---those discouraging ungooey leaves will offer no encouragement. Yes, there are infrequent times the plant looks like a normal sundew, but those are rare days to live for.

I have only been able to propagate this plant vegetatively. I do not bother with leaf cuttings, instead I use root cuttings laid horizontally just beneath the soil surface. I must rarely do this because my plants are always producing plantlets for me. These volunteers spring from the roots winding around the bottom of the root-bound container. This is one reason I prefer to use such shallow containers---I think it encourages the roots to make such plantlets (sometimes the winding roots become so large that over time the entire soil ball is pushed upwards out of the pot).

So the good news is the plant is easy to grow, even if it lacks those beloved shimmering ooky orbs. The bad news is that if you want it to flower, you must grow it outdoors. The key is in giving the plant seasonal variations; such annual changes are usually lacking in terrarium cultivation. During the winter I grow my plants with my tuberous and pygmy Drosera. Under these conditions the plant rarely suffers a frost, but they do have a chilly winter. During these months they stop growing and often acquire a dull maroon flush throughout the rosette. By early March tall hairy scapes form (Figure 1). These uncoil until they are about 40 cm (16 inches) tall. Each scape may produce a dozen or more flowers, one per day. The first flower of each scape is always the largest and worth racing home during lunch time to see (Figure 2).

Oh, those flowers! They will take your breath away! Approximately 3--4 cm in diameter and pink to magenta, they will remind you why you love these plants. They even make up for the forlorn leaves so sadly bereft of viscid satisfaction.

Figures:

Figure 1: Drosera hamiltonii. Notice all the scapes are at the same degree of maturity, synchronized by seasonal stimuli. Photograph by B. Rice.

Figure 2: Drosera hamiltonii. Photograph by L. Logoteta.