What is the normal recommendation for your lilies? Eg Oriental lilies can go about 4-6" but I'm not sure if you would have other kinds of lilies.

In general, use that as a guide, then decide if you want the bottom to be more of your bed soil or your current soil below the bed.

I have asiatics, L.A.s, orientals, trumpets, O.T.s, old-fashioned martagons, nepalense, tenuifolium, and some speciosum Rubra, enough variety to have blooms all summer. I guess I'll go with 1 ft of soil if I can make the bed that deep.The planting box will be on plastic. I like to plant spring bulbs at the top of the hole, with lilies underneath. I'm thinking of making a separate bed for the O.Ts. They are my all-time favorites and I think I have all of them (until the next one is bred).

The typical planting depth recommendation for lilies is that the bulbs are covered with twice their depth of soil up to a maximum of 6-8". For example, a 2" tall bulb will be covered with 4" of soil.

I should think a bed of 10-12" should accommodate just about any lily. I would avoid putting plastic underneath as that could impede drainage and above anything else, lilies - like most other bulbs - require perfect drainage. I would also caution against intermixing spring blooming bulbs with lilies in the same raised bed. Spring bulbs, like narcissus and tulips, go dormant in summer and want to be kept dry. This is the peak of the lily season when they want routine watering. One or the other is not going to be happy.

Hi sunny day
Just had several rainy days here in MA
Your raised bed is interesting --any chance of getting a few
pictures-- I bought one 3 yrs ago and it may last one more yr. with our snowy winters and cold wet Springs
Have been wondering what to do to replace it--anyone with
ideas would be appreciated- Now at 73 am hoping to get
something really high -possibly a seat along side -for old
lady gardeners--
Have a good day, Mari

Late in replying to Mari66's post. Raised bed is made: 4x8 ft, and 2 ft deep. Handyman nailed it together quickly and inexpensively. I decided to put it directly on the soil and plant spring bulbs too---daffs, tulips, crocus.

for mari66.....some pics of raised flower beds from craigs list....the three tier is great for those of us who cannot bend down so good anymore!! guess I don't know how to include more than one picture...