Maybe a few dwarf conifers ? (see link below)

Here is a link that might be useful: dwarf conifers gallery

What you have is more of a container gardening. I do think that since you already have one rose bush, why not pair it with another rose bush and align the box with with lavender herbs or marigolds. Interplant with verbena bonariensis (you could sprinkle seeds),

In container gardening, you can experiment with plant combination as much as you want. With roses however, these are divas in any garden. They need taking care of, and they hate to compete with other plants for nutrients. Because they are in a limited space, you need to choose companion plants that won't compete for nutrients and water. Lavenders are drought tolerant plants. Dont' like being overwatered and you can neglect them. Marigolds help to deter insects. - Verbenas will produce any airy feel to the box and if your lucky, attract butterflies. Whatever you choose, don't make it a tight compacted. Roses require lots of air movement to keep mildew and black spot infections down.

You could also experiment in vertical gardening. Produce a trellis or a tuteur and plant clematis which can grow upwards. Rose & clematis plants are commonly paired together.

It's not easy to conceive roses without thinking of cottage gardening and with cottage gardening, you have lots of possibilities for companion plants. That includes annuals such as snap dragons, delphiniums, daisies, nicotiana, herbs such as rosemaries, parsley, sage, etc...

So the possibilities are endless. Try out anything.

I've been growing all my plants in containers for about 20 years, and I have discovered that there are very few things that you cannot grow that way. There are several things that need to be kept in mind though, regardless of what you're growing.

Firstly, containers tend to dry out faster than you'd think, even large ones. You will need to water probably every day in the hot part of summer, and possibly twice a day. Chose plants that don't require constantly damp conditions - shade plants like Hostas and ferns would be very bad choices. Most herbs like lavender or rosemary love hot dry conditions and would be very good choices. Oregano and sage can grow quite large, look shrubby, have cute little flowers and should come back every spring. Lavender should come back if you pick a hardy variety (you're warm enough that most lavenders should be fine). Rosemary will have to be brought indoors over the winter or bought new in the spring.

Secondly, they get hot. The ground tends to regulate the temperature of roots and keeps them from getting too hot. Plants grown in above ground containers tend to get heated by the sun to a greater degree and some plants cannot tolerate this well. Clematis can be tough to grow in a container that gets hot. I find the easiest Clematis to grow in this sort of container are the alpine varieties and other smaller flowered ones. Most conifers don't do too well in a container that gets hot either. Purple coneflower (Echinacea), daylilies, ornamental grasses, and lots of annuals like Heliotrope and geraniums do very well in this sort of environment.

Thirdly, plants in containers need to be chosen with a little more care if you want them to come back the following year. Plants in containers are more likely to freeze than plants in the ground are. Your box is quite large, so for the most part this won't be a big problem for you (the smaller the container, the more of a problem this is), but you would have better luck if you stick to plants that are rated for zone 5 and lower.

And as Ianna said - think vertical. that means you can also plant trailing vines like vinca and ornamental sweet potatoes to trail over the edge and down the front. Some vines are quite invasive (vinca), but will come back year after year, and they're easy to control in a confined area like a large planter. Non invasive ones like the sweet potatoes would have to be replanted every year.

BP

Hi BP,

I think that what is perhaps described here is a box with no bottom set directly on top of garden soil. Tamanna please advise if this is the case. Also please advise as to depth of the box. The taller the box - the more exposed the roots to temperature changes. The lower the box, the less danger of heat or cold exposure becuase the roses' roots would grow deep beneath planter level.

I had a similar box planted with a climbing rose and clematis. It was about 1 foot tall and it was wide. Because it had an open bottom it was very roomy, I managed to grow several more perennials in it and also some annuals - but I took care to use only shallow rooted plants. hence no competition for space, water and nutrients. Wild thyme looked really great, especially when pruned to shape. Looked like mini-hedges.

Ianna

Ianna - good point! If it's basically a raised bed, it's a much more flexible situation than if it the roots have no access to the ground beneath.

BP

Hi,

I think the box sits about a foot heigh. As for the depth, I would think it is set directly on natural soil, so I don't think there is a bottom to it.

That's a much better situation than what I originally thought - you're not going to have as many problems with heat, cold or drying out.

There are several fruiting shrubs that you can consider. Currants, raspberries or blackberries will grow well and come back (they will all need some pruning every year). There are some miniature fruiting trees available - your local nursery should have at least an apple or two. If you feel like something amusing, try growing a cantaloupe melon vine there - they'll love the raised bed effect.

There are tons of flowering shrubs you can plant and that require minimal care (note that *all* plants require some care - pruning, watering, fertilizing). A small Forsythia is pretty and easy to grow. While 'Night Blooming Jasmine' is a beautiful plant, it's not going to survive the winter there - you'd have to take it inside. Mock Orange is a nice scented flowering shrub that would do well in your box, and it will come back - it will require pruning to keep it manageable though.

BP

Just a point concerning raspberries & blackberries. These produce underground runners and may take over the box. If Tamanna wishes to plant these, it should be kept in a separate container.