Gardening Journal: Plant of the month – Iris Silver edge

June is one of the highlights of the gardening year, so many plants in flower with their foliage still looking vibrant and green. It’s a great time for getting out and getting some fresh inspiration by looking at what others have been up to in their own gardens. Check out The NGS Yellow Book Scheme where you will find some gardens local to you that open their gates for charity.

Plant of the month – Iris Silver edge

Although impressive and incredibly decorative, I’ve never been a massive fan of Iris due to its short-lived flowers which are then followed by scrappy leaves which turn brown and tatty. Just when you want your plants to look vibrant and full of colour, Iris fade and often leave a weak point in the mid-summer border. For this reason, I didn’t use them in planting schemes for years ...until I met Silver Edge.

This Siberian is super-beautiful, especially when viewed from above. Each classically coloured, cornflower blue petal is finely edged in silver, giving the Siberian Iris a whole new look of refinement. It’s an exquisite hybrid, with more appeal than any of the other Iris I have seen in the past. Its foliage also tends to stay green through the summer fitting in with the other plants in the border by providing contrast in texture with its sword shaped leaves.  Give it good soil and a sheltered position and it will shine at the front of the border or in the middle of the border any time of year.
Plants in the Siberian Iris group are chiefly of hybrid origin, primarily being derived from two blue-flowered Asian species, namely, Iris Sibirica, from central Europe, Turkey and Russia and south-eastern Russia, and Iris Sanguinea, from Russia, Korea and Japan. Siberian Irises are the ones that form an elegant clump of tall deep green grass-like leaves, with flowers on long stems that open above the foliage. With flowers somewhat smaller than the huge Bearded Iris, these are the ones that are the easiest to grow and return dependably each year with more and more flowers. They are also, generally, pest-free.

Siberian Iris are excellent at the waterside as they are tolerant of wet sites and will even grow in the shallow water at the edge of a pond or stream. However, if they get enough moisture during the heat of the summer, they can work well in a mixed border too.  Massed planting and well-placed specimens can enhance almost any setting, and the foliage provides lasting beauty after the flowers have faded.

I generally use Iris Silver Edge mixed with other perennials where its foliage also creates drama and contrasting structure later in the year. A great combination for a damper site would be to plant Silver Edge with Ligularia The Rocket, the large leaves of the Ligularia contrasting well with the sword shaped leaves of the Iris. On a slightly drier site I would use Silver Edge with Sedum and Aster where again the foliage creates a great back drop for the late summer perennials, whilst still providing a blast of colour earlier in the year.

Jobs to be doing this month include:
Ornamental Garden:
• Lightly trim box balls – traditionally on Derby Day 6th June!! Would be nice to encourage the box topiary to grow larger while retaining the shape.
• Deadheading – Salvias as the flower heads go over, penstemons, roses etc.
• Spray any plants infected with aphids or black fly.
• Weed!!!
• Prune early flowering clematis.
• Cut back foliage of tulips.
• Trim other shrubs to shape as necessary.
• Plant warm season grasses such as penisetum and panicum
• Treat bindweed/groundelder and other invasive weeds growing among other plants by applying a glyphosate based weedkiller to their leaves.
• Prune ornamental cherries after their flowers have faded.
• There is still time to sow quick germinating annuals such as cosmos.
• Sow winter bedding such as violas etc.
• Cut back oriental poppies/pulmonaria etc after they have flowered. Remove all leaf as well to allow for fresh leave to sprout.
• Remove reverted shoots form variegated shrubs etc.

Vegetable Garden:
• Direct Sow carrots for autumn and winter harvest
• Sow Florence fennel and chicory.
• Plant out leeks once they are pencil thick.
• Put straw round strawberries.
• Water potatoes for good sized tubers.
• Feed tomatoes regularly
• Ventilate greenhouse.