What Is Rockrose?
The rock rose is a spring wildflower from which its name derived. It blooms during the first warm days of spring, giving color to otherwise dreary winter days. Its delicate pink flowers pop up through the snow, signaling that brighter days are ahead.
Rockrose Care & Maintenance:
Rockrose needs light to grow and thrive, but too much sunlight will scorch the leaves, making them look sickly.
Rockroses clamoring over a wall in a garden designed by Sally-Ann Berk of Herbs for Kids Too little water can also cause this plant to wilt and suffer, so water rockrose once or twice a week when it’s not raining.
Rockroses are easy to care for – just follow these tips! (photo: Kaleido Gardens) #3. Rockrose is not picky about the soil it grows in, but make sure that it’s slightly acidic with good drainage. To test your soil pH, you can purchase an inexpensive, color-changing
Light Requirements:
Rock Rose needs at least 6 hours of sunlight daily.
Rockrose can be grown in partial shade if you don’t receive enough sunlight in your home location. (photo: Kaleido Gardens) . Rockrose grows best when it’s planted into loose soil that drains well (avoid heavy clay soils).
Avoid planting rockrose too deep – plant so the longest buds (the newly emerging flower stalks) are just above soil level and leave 2 inches til 4 inches between plants for good air circulation and growth.
If possible, give each plant a little extra growing room by tucking them into a small patch of ground between other plants that they can grow up through to create a leafy cascade effect as pictured below!
Water Requirements:
Water thoroughly during dry spells (when you don’t get at least 1-2 inches of rain each week). You can also water the plants with a handheld sprayer to give them a good soak instead of leaving them in standing water.
Watering Tips:
If you plant your rockroses while there is still snow on the ground, be sure that you won’t disturb the roots when watering. Rockrose has shallow roots and can easily be disturbed by foot traffic or irrigation so avoid stepping too close to the plant until after it has had time to acclimate itself to its new location.
After they are established, rock roses like deep watering once every 2-3 weeks for about 10 minutes or so but do not leave the water sitting on the leaves or roots.
Deep watering loosens the soil and encourages better root growth, which then allows the plant to be more drought tolerant and able to bridge dry spells much easier than a shallowly-rooted plant would be able to do.
Soil Requirements:
Rockrose grows best in slightly acidic, sandy loam soil with good drainage. If your soil is heavy and clings to the roots, add some well-rotted organic matter such as compost or manure to help loosen it up so water can drain more easily through the soil.
Planting Rockroses:
We recommend planting rockrose once temperatures are staying consistently above 50ºF (10ºC). In northern climates this would be around early April; further south it could be planted even earlier, at least 1 month before the average last frost date for your area.
Seedlings:
Rockrose seeds like to stay moist while they’re germinating but once their first true leaves appear it’s important that you let them dry out between waterings. Protect seedlings from cold temperatures by placing them in a sunny window where they’ll get lots of light but not too much heat.
Rockrose planted in patio container (photo: Kaleido Gardens) Seedless, or nearly so, rockroses can be propagated and grown as perennials with summer dormancy just like other perennial herbs such as lavender and rosemary.
Rockroses need to come into growth in order to bloom, which is why we recommend planting new plants every year for the abundant spring blooms. In colder climates it may take longer for your rockrose seeds to germinate; if you’re having trouble getting them started try adding extra warmth such as a heating pad under the soil or fluorescent light (15-20 inches above and no closer than 6 inches from the plant).
They will be easier to germinate if you start them outside in larger containers such as 1-gallon pots under a grow light or in trays that allow for plenty of airflow. If you can’t start your seeds early enough, they may be started indoors 4 weeks before the last frost date. Keep your seedlings on a sunny, south-facing windowsill where they’ll get at least 6 hours of direct sunlight each day.
Temperature and Humidity Requirements:
Rockrose grows best in cool weather (60-70ºF / 15-21ºC, humid) but can survive temperatures as low as 30ºF (-1ºC), although it won’t bloom until the temperature rises above 60°F (16°C).
It also likes to go a bit dry between waterings, especially when young; once established and growing well you should be able to leave it alone without water for 2 or more weeks.
Humidity requirements: Ideal humidity levels are 40-50% but rockrose will tolerate much lower humidity levels. If your humidity is below that range consider placing your plants on a tray of pebbles with water at their bases or misting them lightly every day with room-temperature water.
Fertilizing Requirements:
Rockrose is very forgiving, especially young plants. They like being fed monthly with a balanced, organic fertilizer such as fish emulsion (every 2 weeks) or worm castings (once per month).
Once established they’ll grow fine without additional fertilizer.
If you choose to fertilize them at all it’s best to use a diluted solution and apply the fertilizer directly on the soil around their roots, near their drip line(the widest point of the plant), once every 2-3 weeks but do not spray it directly on the leaves because this will damage them!
Pruning Requirements:
To encourage bushier growth during warmer months pinch your plants back by about 1/3; this encourages lateral branching so new flowers will be produced on new shoots.
Potting and repotting Requirements:
Rockrose is very easy to root from cuttings taken in the spring or early summer. Just find a side shoot that’s about 4 inches long and snip it off with some of its roots attached in a bright area where they can have the best light possible; put them in pots filled with potting soil and place them under a grow light on a heat mat until new growth appears (usually takes 1-2 weeks).
When repotting your established plants (in either late fall, winter, or early spring) be sure to use fresh compost. Tip: If you’re trying to choose between several rockrose varieties for your garden consider how they’ll look together once their mature sizes are compared. Two ssp varieties will
Rockrose Propagation info:
Rockrose can be propagated easily by seed, and since the plants grow from a corm with no roots or true leaves at all it’s very easy to harvest some seeds in order to start new plants.
Prick out your rockrose seeds once they’re ready for germination (usually after 90 days) and plant them 1/4-inch deep in a well-drained medium that’s been enriched with compost (experimenters take note:
there appears to be some variation between individual seeds when it comes to how many days the germination process takes, so if you find yours are slower than expected don’t worry too much about it).
Although rockrose is usually started under lights, we’ve also found they will tolerate a short amount of direct sunlight so you can even start them outdoors if you prefer. The seeds will need temperatures roughly similar to those required for germination, and plenty of water once new growth appears.
Rockrose Problems:
Caterpillars and aphids are sometimes attracted to rockrose, but they rarely cause enough damage to be a bother; if you notice them simply hand-pick or use an organic insecticidal soap spray.
Powdery mildew can affect plant growth and bloom, but there is no treatment for this problem other than prevention: keep the area around your plants free of leaves in fall (if it’s a bird-attracting variety) and remove any dead foliage as soon as possible after it appears.
