How To Read Plant Label Codes for Watering Needs

Plant tags, labels and catalogs are much more attractive if they use icons instead of text instructions. Much like infographics, it’s a newer direction in communication. I see the good side of it, especially for people who have low literacy or shop with small children and don’t have time to turn the tag around for more information. I could say the drawback is that the more we put in symbols, the less we need writers, but that’s not a rant for this blog post.

As far as I know, water symbols are not standardized. If I’m wrong, I would love to be corrected. I think a standard nomenclature and symbol system for plant watering would be a great service to gardeners.

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Catalogs, seed packets and plant labels use a variety of methods to give us clues about a plant’s water needs.

Most water requirements are represented by a water droplet symbol that’s empty, partially filled or completely filled. My summary of similar legends, like the one used by the Albuquerque/Bernalillo County Water Authority, provides the following clues to irrigation:

Empty drop: A plant that requires only rainwater or no supplemental watering once established. So be sure to give a new or transplanted tree or bush extra water until it appears healthy. This can be up to a year for trees and some bushes. After that, there’s no need to irrigate the low-water plant at all. Half-filled drop: This is a medium-water plant. It will always need some supplemental water, depending on what Mother Nature delivers. Most medium-water plants need supplemental water once or twice a month during the hottest days of summer.

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This seed packet shows the moderate water needs of a sunflower.

Full drop: I am not familiar with these plants. Seriously, they usually aren’t going to make it in places that deliver little rainfall, and if they do, it’s not water-wise gardening. But they often can survive in the right climates and conditions, maybe in a welled spot or container, or where there’s run-off from a streambed. Of course, if you live in a tropical area, that’s just not fair. There are additional variations on these labels, like partially filled drops. I’ve also seen use of watering pails as symbols. Most add text alongside the icons, but if in doubt, ask for help from the nursery staff or a local master gardener.

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And because I have to include a pretty flower picture, here’s a portulaca bloom. I love these low-water heat lovers.

No matter what the label shows, circumstances can affect water needs, so don’t take your water icon at face value! Aside from plant establishment, wind and unexpected heat waves can dry plants out. Summer monsoons can nearly drown our drought-resistant plants! And welling and mulching around plants helps them retain water, maybe helping you push a half-filled drop to a quarter-filled one…

Four low-water Container Plants

I love pots! Actually, I love any kind of container that will hold a plant. We’ve been known to grow herbs in a claw-foot tub and annuals in an old washer. When you grow plants in containers, you increase your flexibility – you can move the container with the sun (maybe not the claw-foot tub so much…) and have color in a shady location by your front door. You also can practice “flower arranger,” creating a few new containers with each season’s annuals, or putting together a group of perennials you can keep outside all year or winter over.

Here are a few favorite low-water plants that grow well in containers:

Verbena (Verbena tenuisecta). Verbena species vary, but the warm-zone, low-water species can grow with very little water. They came up through the gravel pathways in our rock garden, re-seeding from previous years. I’ve planted small varieties of red, white and rich purple verbena in containers. Once established, verbena will spread and using it in container groupings helps tie them together or add pops of color. Verbena requires no deadheading, though removing spent flowers can prolong the bloom period, which usually runs from spring through frost, depending on your zone.

purple verbena
Verbena looks great alone or as part of a group planting. This magelana violet variety, and the photo, is courtesy of PlantSelect.

Chocolate flower (Berlaniera lyrata). Great in a rock garden or container, a chocolate flower always pleases. And in case you’re wondering, it really does smell like chocolate. I ought to know. Anyway, chocolate flower is a wildflower that produces delicate, daisy-like flowers with a light, almost red, center. Its leaves are a pale, almost silvery green. It’s extremely drought tolerant. Planting it in a container means you can enjoy its scent right on your patio or outside an open window.

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I love the chocolate flower buds; they’re delicate and different. Image courtesy of PlantSelect.

Rosemary (Rosmarinus officinalis). Rosemary is equally pleasant smelling and actually edible! I grow it every year in a container, and have several plants growing as ornamentals in our garden. It has evergreen foliage, so if you live in zones 6 to 8, you probably can keep it alive all year in the garden. In zone 6, it also might make it in a container, though I’ve had creeping rosemary burn from cold or snow even in zone 7. So either protect your container or bring it in, depending on the hardiness of the variety you choose. But back to enjoying rosemary! Plant it all alone near your kitchen for easy fresh cuttings, or in a group container. And if you decide not to take cuttings for cooking, your rosemary might eventually bloom lovely lavender colored blooms. At any rate, put it where you can frequently walk by and just rub your fingers over the leaves.

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My rosemary has survived sub-freezing temps so far up against the south side of the house. It still smells terrific, even after the wind blew leaves all over the container.
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Bees love this creeping rosemary, which requires little to no water in a container or landscape. This is all one plant; we had to cut some away in the middle after it burned. We should have knocked the snow off.

Ornamental grass (try blue fescue, silky threadgrass, or blue avena). Who says a plant has to flower to look great, especially in a container? I love adding a spike of height and texture with a grass, often in the center or back of a container full of colorful annuals. Most grasses need less water than flowering plants, and they look great blowing in the wind or adding height to a container, especially one placed up against the house. Many of them even flower. Just be sure to check the tag to see how high the grass normally grows before making your purchase.

And remember that plants always need a little more water when you first plant them, in extreme heat and when in containers than when in the ground. Containers usually dry out more quickly than ground soil – how much more depends on the container, soil you used to fill it and the location. And containers are microclimates, which means they might place your plant in colder, warmer or drier conditions than you realize.