Hyssopleaf Sandmat (Euphorbia hyssopifolia)

Hyssop-leaf sandmat (Euphorbia hyssopifolia) is a sandmat that’s indigenous to the southwestern part of the United States. A sandmat is a plant in the genus of Euphorbia that thrives best in deserts. Hyssop-leaf sandmat has a milk-white sap in its stem—just like the milkweed. It’s also known as hyssop spurge, eyebane, wart weed, and chicken weed.

I. Appearance and Characteristics 

Euphorbia hyssopifolia, known by the common name of hyssopleaf sandmat in English and hierba de pollo (“chicken grass”) in Spanish, is a member of the spurge family, Euphorbiaceae. It is an annual herb, native to Central and South America and the Southeastern United States. It has also been introduced to west Tropical Africa, India, and Australia.

Arching annual to 80 cm with leaf-bases oblique. Flowers and fruits in small loose clusters. Because it is rather confusable with the usually slightly hairier E. nutans, fruit capsules should always be opened for seeds. The seeds are cross-ridged and rather square-edged in comparison to the more irregular rounder-edged seeds of E. nutans.

Seeds: “brown to grayish white, ovoid, slightly 4-angled in cross section, abaxial faces convex, adaxial faces slightly concave to slightly convex, 1–1.4 × 0.7–1.1 mm, with 2–3 prominent transverse ridges that do not interrupt adaxial keel, or coarsely and inconspicuously pitted-reticulate.” FNA (see also FNA nutans)

Poisoning from hyssop-leaf sandmat can occur through ingestion or direct contact, especially with the eyes. Medical attention should be sought immediately as symptoms can range from mild to severe. The poisonous part of the plant is the sap that runs out as a milky liquid. If you ingest the sap you will experience vomiting. Getting the sap into your eyes can cause mild conjunctivitis to severe kerato-uveitis, or even blindness. This is a fairly common weed that is found in gardens, footpaths, lawns, and on roadsides, making it dangerous to children.

II. How to Grow and Care

Sunlight

Hyssop-leaf sandmat thrives best in full sun conditions where it receives direct sunlight for most of the day. This light intensity promotes its healthiest growth and robust form. While hyssop-leaf sandmat can tolerate partial sun, meaning some shade or filtered light, especially during the hottest part of the day, deviations from full sun may result in leggier stems and reduced vigor. In terms of adaptive traits, hyssop-leaf sandmat can adjust its foliage to maximize light absorption. For outdoor cultivation, hyssop-leaf sandmat should be placed in spots where sunlight is abundant. No indoor placement is necessary for hyssop-leaf sandmat, as it is traditionally grown outdoors.

Temperature

Genus Euphorbia is very large and diverse, so its different species can be found in various habitats, but the majority are well-adapted to a temperature range of -29 to 4 ℃. Many spurges, in spite of having succulent leaves, cannot handle long periods without moisture and need to be watered weekly during hot summer days. Some cactus-like species are well adapted to high temperatures and prolonged dry periods, but most species used for landscaping and decorative gardening require more moisture for proper development.

Watering

Originating from tropical regions, hyssop-leaf sandmat thrives in environments with consistent moisture. This species is adapted to a regular water cycle and exhibits a preference for evenly moist soil conditions, without tolerating prolonged dryness. Accordingly, it requires watering every week to maintain its hydration balance. Transitioning smoothly into care practices, this routine ensures that hyssop-leaf sandmat’s needs are met without over-saturating the soil. As an outdoor plant often found in warm climates, hyssop-leaf sandmat benefits significantly from mulching to retain soil moisture during hot periods, linking its growth success directly to effective water conservation strategies.

Soil

Spurges aren’t picky when it comes to soil type. They can grow in a variety of soils. Some species of Euphorbia can even thrive in nutrient-poor soils, requiring only that the soil be well drained. If the soil is full of moisture and is prone to water retention, it will most likely cause root rot.

Fertilizing

Hyssop-leaf sandmat doesn’t require large amounts of fertilizer for normal growth and development. In fact, very little fertilizer is required. As mentioned earlier, some species can thrive even in very poor soils, as long as those soils are well drained. Fertilizer should only be applied when the plants start showing nutrient deficiency symptoms on lower leaves. When the lower leaves turn yellow, it is time to add half-strength liquid fertilizer to the soil. That will keep the plant well fed for several months.

Planting Instructions

Dig a hole twice as wide as the plant’s root ball before planting. Then, turn the container with hyssop-leaf sandmat upside down and let the plant slowly fall into your hands. Place the plant upright in the hole and slowly fill in around the roots with loose and fertile potting mixture, adjusting the planting depth until it is just right. Water it once. Do not overwater, as standing water is not good for the plant.

Propagation

Hyssop-leaf sandmat can be successfully grown from seeds, but the seeds are rarely commercially available because they are difficult to germinate and stay viable only for a short period of time. Hyssop-leaf sandmat is most commonly propagated via cuttings.

It is important to wear gloves while working with hyssop-leaf sandmat cuttings and to clean the pruning shears thoroughly after pruning, so that any unwanted contact with the sap is avoided. Before planting, it is necessary to leave the cuttings to dry for 2-3 days. This will prevent rot from developing and enable proper formation of the callus tissue. It is advised to plant the cuttings in a soilless medium, such as peat moss, because it provides an optimal environment for proper root development.

Cuttings should be misted regularly, and the pots in which they are planted need to be wrapped in either foil or a plastic bag to preserve moisture. The bag or foil needs to be removed for two hours each day to provide sufficient air and to prevent excess moisture in the medium. If this step is skipped, molds and rots can easily develop and damage the health of the young, sensitive cuttings. When the cuttings develop a root system, they are ready to be transplanted into soil.

III. Harvesting and Storage

When harvesting cuttings, remember to wear gloves, as the sap can be irritating to the skin. It can be cut from the base of the stem. Soak the end of the cutting in hot water for 10 seconds to stop the milky sap from oozing. The vase life for the cutting will be about 5-7 days, and some flower food can extend its life.

When the fruits of Euphorbia plants are ripe, they burst and scatter the seeds over a large surface area. In order to harvest all the seeds, the individual fruits or the entire plant must be wrapped in nylon, gauze, or similar material before the ripe fruit bursts and releases the seeds.