I'm talking about clumps of tuberous Iris with the lovely big, blousy flowers early on in the Summer. They often come in blue or purple, but if you go to the website at the wonderful Woottens nursery near Southwold in Suffolk www.woottensplants.co.uk you will see a huge range of gorgeous colours to suit every taste. There is talk of repeat flowering varieties, too. Now is the best time to tackle clumps of iris that have become congested and so stopped flowering generously. That happens here about every 3 or 4 years, but it does depend a bit on the variety, soil and situation.The idea is that, if you do it now, the newly planted tubers will have time to settle in and get a reasonable baking to induce good flowers next year. Iris like good, but very well drained soil, a bit of a hard one to pull off. I dig both grit and garden compost in before re-planting, it works well on our heavy clay spoil. They like a sunny spot, not overcrowded by other plants. Step 1 - dig up the whole clump and get all the weeds and unwanted plants out. Some folk suggest you should not replant Iris in the same soil again, but in my experience as long as you replenish the soil and have had no problems with disease, it is usually fine to do so. Step 2 - throw away the old and nobbly brown middle with no sign of leaves - see left photo. Keep the younger, more vigorous tubers - middle photo, pop them into a bucket of water to keep them fresh and happy while you prepare the ground, dig it over really thoroughly and add compost and grit if needed. Step 3 - when the new bed is ready for them, carefully check over the plants you have kept, trim off the top of the leaves to stop the autumn gales blowing them out of the ground, plant and water well and carry on doing so until they are established - see photo on right. Don't plant them too deep, the tubers need to feel the sun on their faces to make them want to flower.