A truly lovely plant with large pink showy flowers that blooms from late spring until the frost. It is perfect for borders in dappled shade and full sun in higher latitudes. Blooms best in cooler temperatures so picking an area where it wont get too hot or can pick up a breeze is ideal. Not fussy about soil type but does like a well drained soil. Easy to grow it is a perennial but might not survive above zone 7 so grow it there as an annual. Blooms prolifically first year from seed. No garden should be without this lovely plant, looks really exotic.
Description of Chinese Foxglove (Rehmannia elata).
In spring sends out large semi oval shaped leaves of mid green with darker deep
veins and irregular scalloped margin. Large rosettes of leaves then produce
tall stems with large tubular flowers of pink or light purple with gold to orange
centers. Flowers are borne on branching stalks which flower from the base of
the stem towards the top. Flowers are large up to 2" across and 3"
long and bloom from late spring until frost. The plant produces rhizomes which
will overwinter and flower for many years if mulched and protected in colder
zones.
What zone is it hardy to?
That depends on your source. It is certainly a perennial in zones 8, 9 and more.
Zone 7 is unpredictable. It can overwinter if the weather is not too server
but if its colder it will die off. We have had it overwinter in warm winters
and vanish when its cold. The upshot is if you are zone 7 or lower then consider
it as an annual and be prepared to reseed it every year. Once you have grown
it once then you will want to grow it again its such a gorgeous plant with exotic
flowers and it just blooms and blooms. Grows rapidly from seed and blooms in
about 70 days from germination then it keeps going until the killing frost.
Location and Care of Chinese Foxglove (Rehmannia elata).
Prefers to have a reasonable amount of sunshine but since it will flower more
prolifically at cooler temperatures some shade from the heat of the summer is
recommended in Zones 8-11 more shade should be used, and area that gets dappled
sun with through breezes to keep the plants cool should provide the best results.
Somewhere that has full sun in the morning or evening, and shade from noon sun
it best. For zones 7 and higher full sun all day is just fine.
Prefers a rich soil that is well drained. Recommend adding organic material
such as compost to the soil before planting for the best results. Top dress
with mulch over the winter to protect the plants. Take care not to over mulch
and attract voles which love to eat the rhizomes.
Plants can grow to 2 feet wide and 3 feet tall so allow space when setting out
plants. Water daily for best results using a soaker hose or drip irritation.
Can tolerate watering once a week but flowers will not be as prolific.
May tend to flop over after a couple of months so might want to stake it. Mostly
the older flower heads fall over and the newer ones stay upright so you still
get lots of upright flowers. Its going to depend on how you want your plants
to look.
We never stake ours but mostly ours are grown as annuals, when they do overwinter
they are larger and stronger an more likely to need stakes.
Feeding with liquid fertilizer during the summer season will help keep plants
strong and prolific.
In zones where it overwinters it will spread underground using runners and can
be used as a really nice groundcover. It will however die back in winter. Great
for flower borders and cut flowers.
Growing Chinese Foxglove (Rehmannia elata) from seed.
Chinese foxglove seeds are small so sowing indoors is recommended for best results.
Plants can be sown outdoors after all danger of frost has past but
seedlings
may be overwhelmed by weeds.
Sow in good potting soil in small pots, plug trays or seed trays for best results.
See general growing
instructions - small seeds for best results. Germination can be from 15-30
days depending on temperature. Transplant out when plants have reached at least
six inches of height and have been hardened before placing in desired location.
Easy to germinate and grow. May easily self seed.
Medicinal uses of Chinese Foxglove (Rehmannia elata).
This plant is very similar to another Chinese foxglove (Rehmannia glutinosa)
also known as Di Huang which has been used for centuries in Chinese herbal medicine
and is considered one of the 50 fundamental herbs. Little is actually reported
about Rehmannia elata and very little that is definitive. A few sources
state this plant can be used instead of R. glutinosa but I don't feel
they are reliable. The few Chinese sources state briefly that Rehmannia elata
does not have the same properties and is not used. There are no research papers
to date so the best conclusion is that this plant is NOT used medicinally only
for its beautiful flowers. Sadly R. glutinosa is much more difficult
to grow and very hard to obtain. (we are working on it).