Overview
Arabis microphylla Nutt. var. macounii (S. Wats.) Rollins, also known as Small-leaf Rockcress, is a small flowering plant in the Brassicaceae family and is native to North America.
Description
The Small-leaf Rockcress is a low-growing plant, typically reaching heights of 10-20 cm. The leaves are small and narrow, measuring only a few millimeters across and are arranged in a basal rosette. The plant produces small, white flowers that bloom from April to June.
Uses
Small-leaf Rockcress is often grown as a garden plant because of its attractive foliage and delicate flowers. It is also valued for its ability to attract pollinators to the garden. In addition, some Native American tribes used the plant for medicinal purposes, as a poultice for wounds and as a treatment for colds and flu.
Distribution
The Small-leaf Rockcress is widespread across western North America, occurring from British Columbia and Alberta south to California and New Mexico. It is typically found growing in rocky, gravelly soils in alpine and subalpine habitats.
Light requirements
Arabis microphylla Nutt. var. macounii (S. Wats.) Rollins prefers full sunlight to partial shade. The plant typically grows best in areas where it can receive at least six hours of direct sunlight each day. However, it can also tolerate shade, provided that it still receives some sunlight during the day.
Temperature requirements
This plant species is adapted to cool climates and is tolerant of cold temperatures. It can grow in regions where the average temperatures range from 10°C to 20°C (50°F to 68°F) during the growing season. During the winter, the plant goes dormant, and it can withstand temperatures as low as -20°C (-4°F).
Soil requirements
Arabis microphylla Nutt. var. macounii (S. Wats.) Rollins grows best in well-draining soils with a neutral to slightly acidic pH. The plant can tolerate a wide range of soil textures, from sandy to loamy soils. However, it prefers soils with adequate moisture content but not excessively waterlogged.
Cultivation Methods
Arabis microphylla Nutt. var. macounii (S. Wats.) Rollins is a versatile plant that can be cultivated in various soil types. However, it thrives best in well-draining, moist soils with a pH ranging from acidic to slightly alkaline. It grows well in full sun and partial shade environments, although it requires a minimum of six hours of daily sunlight to flourish. Propagation can be done by seed or cuttings. Seeds should be sown in the early spring after the last frost, while stem cuttings can be taken in late summer.
Watering Needs
Proper watering is an essential aspect of growing Arabis microphylla Nutt. var. macounii (S. Wats.) Rollins. It requires frequent watering during the growing season, especially during hot and dry periods. Young plants require more moisture, and care should be taken not to let the soil dry out completely.
However, it is essential to avoid waterlogging and overwatering, which can lead to root rot. The best practice is to keep the soil slightly moist, and water deeply once or twice a week, depending on the weather condition.
Fertilization
Arabis microphylla Nutt. var. macounii (S. Wats.) Rollins requires moderate fertilization during the growing season to ensure healthy growth and development. A balanced fertilizer that contains equal amounts of nitrogen, phosphorus, and potassium is recommended.
The first application of fertilizer should be done in the early spring before new growth appears, followed by a second application in late spring. Care should be taken not to over-fertilize as it can lead to excessive foliage growth and reduce the number of flowers produced.
Pruning
Regular pruning is not essential for Arabis microphylla Nutt. var. macounii (S. Wats.) Rollins, but it can help to promote bushier and more compact growth. Pruning can be done in the early spring before the new growth appears or immediately after flowering.
To promote new growth, cut back the top one-third of the stems. This will encourage the plant to produce new shoots from the base, resulting in a more robust and thicker plant. Deadheading, removing spent flowers, can also be done to promote continuous blooming.
Propagation of Arabis microphylla Nutt. var. macounii (S. Wats.) Rollins
Arabis microphylla Nutt. var. macounii (S. Wats.) Rollins, commonly known as Macoun's rockcress, can be propagated through both seed and vegetative methods.
Seed Propagation
To propagate Arabis microphylla Nutt. var. macounii from seed, collect ripe seed pods in late summer or early fall. The pods will split open when they are ripe, and the small seeds can be easily collected and cleaned. Stratify the seeds for several weeks in the refrigerator before planting in the spring. Plant the seeds in a well-draining soil mixture, and keep the soil moist until germination, which typically occurs within two to three weeks.
Vegetative Propagation
Arabis microphylla Nutt. var. macounii can also be propagated through vegetative methods such as cuttings or division. To propagate through cuttings, select healthy stem cuttings with several nodes, and dip the cut ends into rooting hormone. Plant the cuttings in a well-draining soil mixture, and keep the soil moist until roots develop, which typically takes several weeks.
To propagate through division, carefully dig up the plant and separate the root ball into several smaller sections, each with a few leaves and roots. Replant the sections in a well-draining soil mixture, and keep the soil moist until the plants become established, which typically takes several weeks.
Disease and Pest Management for Arabis microphylla Nutt. var. macounii
Arabis microphylla Nutt. var. macounii is a hardy perennial plant, but like all plants, it is still susceptible to diseases and pests. Here are some common ones that might affect the plant and how to manage them:
Diseases:
Anthracnose: This fungal disease causes brown spots on the leaves, stems, and flowers of the plant. To manage anthracnose, it is important to maintain good air circulation around the plant. Remove any diseased leaves or stems and dispose of them, and avoid wetting the foliage when watering.
Downy Mildew: This fungal disease causes yellow or white spots on the upper surface of leaves, with grayish-white growth on the lower surface. To manage downy mildew, avoid overhead watering and provide good air circulation around the plant. Remove infected leaves and dispose of them.
Root Rot: This fungal disease causes the roots of the plant to become mushy and dark-colored. To manage root rot, do not overwater the plant and make sure that the soil is well-draining. Remove any plant debris from around the base of the plant.
Pests:
Aphids: These small insects feed on the sap of the plant, causing leaves to curl and distort. To manage aphids, spray the plant with a strong stream of water to knock the insects off, or use insecticidal soap or neem oil.
Spider mites: These tiny mites feed on the sap of the plant, causing leaves to become speckled or yellowed. To manage spider mites, increase humidity around the plant by misting it regularly, or use insecticidal soap or neem oil.
Slugs and snails: These slimy pests can eat holes in the leaves of the plant. To manage slugs and snails, handpick them off the plant or use bait traps. You can also create a barrier of coarse material, like sand or crushed eggshells, to prevent them from crawling onto the plant.
By being vigilant and proactive in managing diseases and pests, you can help keep your Arabis microphylla Nutt. var. macounii healthy and thriving.
