Hi Deb18, I pick out several problem with the Lily BULBS in the growing conditions you have given them.
I agree with Diana's views on the watering regime, Lily bulbs can get rot and mould set into the bulbs IF sitting in wet or too damp soil, I live in a high rainfall area and for Lily's to grow and be left in the open garden I have to dig a hole way deeper than normal as I need to add lots of horticultural sand or small grit to the bottom of the planting holes, this allows any excess water (rain or hand watering) to drain well away from the base of the bulbs. I would then feed the bulbs by scattering handful of blood / fish / bonemeal, this is sold ready mixed at garden store, but, never over feed, I like to add this feed early spring. this boosts the energy and gives nutrients my type of soil lacks.
You need to deadhead the seed pods after the flowers are over, any plant under stress, or showing problems as your's are wont want to then use lot's of energy setting seeds, unless you want to grow more plants from seeds, of a particular plant, it's weakening the plant by allowing seedheads to form. The other thing, IF you do want seeds, always make sure the parent plant is healthy as any diseases will make for poor germination and even the possibility of the same diseases being passed onto the seedlings.
The Black /Browning within the foliage can be signs of several things,
1. mould attacks because not enough air able to circulate the base of the plants.
2. Insect attack, looking for things like small sap sucking flies, Aphids come in shades of green, white, black etc, they suck out the sap from the foliage and the foliage dies off sometimes going slime to the touch, sometimes going crispy, sometimes just falling over like yours, so have a good look ALL OVER the plant for tiny beast's.
3. Lastly, Lily's are regularly attacked by a BRIGHT RED BEETLE, called Lily Beetle, these beetles have a give-a-way sign that they excrete POO that is soft BLACK in colour and it lays on the stems, foliage etc, so again, look for this to let you know IF you have got this problem, the beetles are a beautiful bright red, they do fly but mostly you find the clinging onto the creases between the leaf and stem. to remove these red bugs, hold your hand under the area and try drop them off the plants onto your hand, drop them to the ground and stamp on them immediately as they do run / hide away very fast. I know of no other products that kill this pest BUT I don't use chemicals anyway.
My last bit of advice IF I were you would be to lift the bulbs, search the bulbs for damaged bits for rot, soft or brown bits, the bulbs should feel firm, look healthy and you leave the foliage attached, remove seed heads, pot the bulbs up into pots of good quality bulb compost from store, don't plant more then 3 bulbs per pot, just encase there is a problem with the bulbs, this prevents loosing ALL the bulbs. make sure there is drainage holes in bottom of pots, water them and leave alone till the foliage has dried, turned yellow or brown, gently tug and tease the dried foliage free from bulbs.
Place the pots in a shaded area, end of season store the pots indoors / garage / hut / basement etc. next spring bring the plants out from the winter storage and when you see the tiny green tips show through the soil, either plant them in a sunny but well drained soil to bloom again next summer, that is IF the bulbs are disease free and healthy.
Hope this helps you out a bit and things are NOT as bad as they first look.
Kindest Regards.
WeeNel.
