A steadfast flower for a shady area of the garden, busy lizzies or impatiens (Impatiens walleriana) grow outdoors when temperatures are warm and frost never threatens. Tropical in origin, today hundreds of different cultivars offer various mature plant heights and flower petal colours, ranging from white to shades of pink, fuchsia, salmon-orange and magenta-red. Busy lizzies are frost-tender perennials, always grown as seasonal annuals in the United States.
Plant busy lizzies outdoors after the threat of frost passes in spring across most of the continental United States. Wait until the soil warms up to at least 21.1 degrees Celsius. Chilly soil and air temperatures stunt growth of busy lizzies. About the same time gardeners plant sweetcorn, peppers and tomatoes outdoors is the time to plant busy lizzies outdoors, too. Continue to plant them up until about six weeks before the expected first frost in fall or winter.
Busy lizzies' stems are succulent but weak and flexible. Soil must remain evenly moist, otherwise the stem and leaves quickly wilt. Severe heat coupled with dry soil will kill busy lizzies, so do not plant them with more than an hour of direct sun from spring to fall. In tropical regions such as Hawaii, coastal Southern California and South Florida, it's best to plant busy lizzies in fall and winter. The cooler temperatures, lack of frost and weaker sun rays allow them to grow well without excessive watering. In cool summer regions at high latitudes, busy lizzies may tolerate a lot more direct sun without wilting.
The best garden soil for busy lizzies is loam with lots of organic matter such as compost or well-rotted manure. Both sandy and clay soils benefit from organic matter to improve drainage and nutrition. Avoid dry and soggy soil areas, as both lead to plant stress or disease. Planting impatiens under large trees can be difficult, and the many tree roots may create a dry soil that leads to the death of impatiens, evenly though it is shady and cool.
If you grew busy lizzies in your garden last year, you may find random seedlings called volunteers popping up around the landscape in spring once the soil and air warms up. A warm early spring may coax seed germination and potential for seedlings to be killed by an untimely frost. However, busy lizzies drop so many seeds that others will likely sprout later in spring and into summer to fill in bare soil spots like weeds.