divided iris had not been divided for probably ten years and were severely overgrown amended soil with peat moss, compost bone meal and low nitrogen fertilizer. Shortly after dividing the garden became choked with weeds and had to dig up and replant. Wondering if ph is factor but usually iris are not that fussy about ph.
They probably need more time to establish after replanting twice. These articles may help:
https://www.gardeningknowhow.com/ornamental/bulbs/iris/dividing-transplanting-iris.htm
https://www.gardeningknowhow.com/ornamental/bulbs/iris/divide-bearded-irises.htm
You don't need to, although many people do to clean up the garden in the fall. If you are transplanting the iris, it may be helpful to cut them back to about 6 inches for ease of planting.
This can happen if they are not planted deep enough. They will fall over.
Here is a collection of articles that will help you:
Should I not weed and cut the this fall
Weeding is fine, but I would not prune unless they are diseased, anyway. Spiders are beneficial, but weeds will be counterproductive.
As long as you leave what is on the Irises, physically, then removing the rest shouldn't cause too much of an issue.
Here are some articles that will help:
Since we live in San Diego, we have very mild winters and I know that I don't have to dig up the bulbs for the winter but do I need to continue watering, water less or not at all? Thank you
That depends on whether you receive much moisture through the winter. If you get rain about once a month that should be sufficient for this time of year. Since neither one is blooming and it is cooler, the bulbs may rot if they get too much moisture. If you don't get rain in a month, go ahead and water.
Would starfish iris grow outside in the ground in zone 8b or would they need to be in a container that would be brought inside in winter? (I am thinking of sending as a gift)
Starfish iris cannot take a freeze and are hardy in zones 9 to 11. You are right on the edge, so if you want to try to plant them in the ground, be sure they are mulched well and sited in a protected area, preferably on the south side.
They can easily be planted in pots and grown inside. No need to summer them outside because they are dormant in summer. Here is more:
https://www.gardeningknowhow.com/ornamental/flowers/starfish-iris/growing-starfish-iris-plants.htm
What would cause my Iris plants to have brown tips. I have 3 one of which is getting ready to bloom all three have brown tips would like to know what to do ti get rid of
Brown tips on leaves can result from a freeze injury. New growth will be normal. It also could be iris leaf spot or the beginning of soft rot. These articles should help:
https://apps.extension.umn.edu/garden/diagnose/plant/annualperennial/iris/leavesspots.html
https://www.gardeningknowhow.com/ornamental/bulbs/iris/iris-plant-care.htm