Diana Cox's notes on growing Irises
I feel sure you all know Horticulturally:
Alkaline soil has a reasonably high PH, notably about PH 7, 7.5, up to 8.5
Acid soil has a lower PH, about PH 5, 5.5 to 6.5.
Add lime to soil to make it alkaline add agricultural sulphur to soil to increase its acidity.
You will notice from the Different Types & Species of Iris, that the Bearded Iris (known as Pogon Iris), require lime for alkaline soil while the Beardless Iris (Apogon) require Acid soil, so avoid ANY lime.
Bearded Iris like manure incorporated well into the soil but NO MULCH or manure beside or on their rhizomes. They like to bake in sun in summer & freeze in winter! Constantly wet feet disastrous.
Beardless Iris (Water Iris) are heavy feeders & always thirsty. Feed often, say monthly, stand in water. Late Spring flowers.
Iris Evansia (several types: Iris Tectorum, Iris Japonica, Iris Gracilipes (Daylilies), small basically white flowers, some pale blue, can be a permanently cool green groundcover with many dainty flowers opening in late winter/early to late spring. Last well in vases indoors.
Fertilizer recommended: Yates Flower & Fruit or Yates Tomato food for flowering—same PH reading
Bearded Iris are great companions for Roses with similar tastes for alkaline soil.
Beardless Iris increase rapidly with strong rhizomes, in pots or in the ground.
A Bog garden is a good solution mixing Louisiana Iris with Iris. Pseudacorus, Iris. Virginica & Iris Versicolor, Gerald Darby, Iris Laevigata & even deciduous Japanese Iris, which are completely dormant in winter.
Don’t forget Iris Unguicularis, (Algerian Iris, Winter Iris), which grows in grassy clumps with Blue flowers (occasionally white or rose pink, ) tolerates shade or sun and is dry-tolerant. Don’t cut the flowers, pull them by their stalk & buds will open inside in the vase.
You can download and print this document:
Alkaline soil has a reasonably high PH, notably about PH 7, 7.5, up to 8.5
Acid soil has a lower PH, about PH 5, 5.5 to 6.5.
Add lime to soil to make it alkaline add agricultural sulphur to soil to increase its acidity.
You will notice from the Different Types & Species of Iris, that the Bearded Iris (known as Pogon Iris), require lime for alkaline soil while the Beardless Iris (Apogon) require Acid soil, so avoid ANY lime.
Bearded Iris like manure incorporated well into the soil but NO MULCH or manure beside or on their rhizomes. They like to bake in sun in summer & freeze in winter! Constantly wet feet disastrous.
Beardless Iris (Water Iris) are heavy feeders & always thirsty. Feed often, say monthly, stand in water. Late Spring flowers.
Iris Evansia (several types: Iris Tectorum, Iris Japonica, Iris Gracilipes (Daylilies), small basically white flowers, some pale blue, can be a permanently cool green groundcover with many dainty flowers opening in late winter/early to late spring. Last well in vases indoors.
Fertilizer recommended: Yates Flower & Fruit or Yates Tomato food for flowering—same PH reading
Bearded Iris are great companions for Roses with similar tastes for alkaline soil.
Beardless Iris increase rapidly with strong rhizomes, in pots or in the ground.
A Bog garden is a good solution mixing Louisiana Iris with Iris. Pseudacorus, Iris. Virginica & Iris Versicolor, Gerald Darby, Iris Laevigata & even deciduous Japanese Iris, which are completely dormant in winter.
Don’t forget Iris Unguicularis, (Algerian Iris, Winter Iris), which grows in grassy clumps with Blue flowers (occasionally white or rose pink, ) tolerates shade or sun and is dry-tolerant. Don’t cut the flowers, pull them by their stalk & buds will open inside in the vase.
You can download and print this document:
| diana_cox_iris_notes.pdf |