Answer: In my experience, it is usually a good idea to wait a full year before trying to add or change large aspects of an extensive existing garden. You may find, for example, that quantities of bulbs appear next spring since many bulbs such as crocus and daffodils are extremely long lived and increase generously over time. If not, you can use that time to look and see where their addition would be most pleasing, make a note and plant them the next fall. Documenting the progression with photos will also be helpful for deciding what to keep or increase (or get rid of) and in identifying the plants.
In the meantime, perhaps an experienced gardening friend or gardening neighbor could help you identify the plants you already have and note if they have any particular special needs. Another approach would be to visit display gardens and see if you can identify the plants you have, then either ask about them or look them up in a book.
As a rule of thumb, perennials (flowers that come back from the roots each year) can be cut back to about four inches in late fall once frost has killed back the tops. Annuals (those that die in winter and are replaced each spring, such as marigolds, petunias, geraniums, zinnias, sunflowers, etc.) are simply pulled up each fall since they will not survive the winter. Flowering shrubs are usually pruned right after they bloom, if any pruning is needed.
Roses present a special problem in this instance since care will really depend on whether they are hardy shrub roses or the much more delicate hybrid tea roses. You might ask your neighbors if they have noticed special measures taken for the roses in the past (such as rose cones or other extensive protection measures) and if so, then follow through with that as they are probably the hybrid teas. Otherwise, a heavy mulch over the root zone should be adequate. Rose pruning is also specific to whether to stock them as well. Your county extension may also offer gardening information and be a source of helpful advice for you.
As with most things, too, we learn a lot about gardening as we go just through trial and error. That is part of what makes it interesting and fun. You will also find that most people who garden are very happy to share their experience (and opinions) about what to do.
Good luck with your new garden, I'm sure you will spend many happy hours in it.
or not these are hybrid tea roses, but this is a problem you will need to address in the spring rather than now. The book Roses for Dummies includes excellent rose care instructions and clear diagrams showing what to do and how. Another approach is to work with a local consulting rosarian from the American Rose Society to identify your roses and learn to care for them.
For general garden bed maintenance, a late fall or early spring application of compost is usually a good idea, as is maintaining a layer of about three inches of organic mulch year round. These will help maintain organic matter in the soil as they break down over time.
For the same purpose, fall is a great time to start a compost area so you can collect and save the falling leaves as well as lawn clippings any other organic material (disease and pest-free as well as herbicide-free) you clean up in the fall. The leaves take far less room if chopped (you could use the lawnmower for this) and can eventually be used as mulch.
You might also apply a general purpose fertilizer in the early spring such as a granular 10-10-10 according to the label instructions. However, it is a good idea to run some basic soil tests and see if you actually need to fertilize and in what proportions -- it is better to underfeed than overfeed. Your county extension or local professionally trained nursery staff should be able to help you with soil tests and interpreting the results.
There are numerous books out there, but I do recommend the Dummies series; it includes numerous books on different aspects of gardening including the general Gardening for Dummies where you should probably start, then depending on what is in your yard look at Perennials for Dummies, Annuals for Dummies, Flowering Bulbs for Dummies, Roses for Dummies, Lawns for Dummies and so on. They are widely available in paperback and most libraries seem
Q&A Library Searching Tips