Here are a few tips for folks who want to include gardening, specifically rose gardening, in their writing.  It may help writers to avoid some of the more egregious mistakes.

What your characters would have known...

Some of you indicated your characters in your books need to be familiar enough with roses to be involved in hybridizing them, or even growing them in profusion.  If they are doing this, then there are a few areas which you may already know, but may not be aware that you know.

REPRODUCTION AND TIME
Raising roses takes time.  This means that your heroine/hero can't just decide to raise a new variety of roses and a year later be selling them.  Here are some general guidelines:

• Reproduction by seedling is for creating new varieties of roses.
• Reproduction by grafting/budding/inoculation is for creating more of one variety of rose, so you can sell it. 
• Reproduction by layering or suckers can be used for creating more of one variety of rose, so you can sell it, BUT more importantly, use this method to create more original roses to create more bud eyes to create the quantities required to sell. The quantities produced by these methods will be fewer than by grafting/budding/inoculation, but can increase your breeding stock as opposed to selling stock.

So, let's say you have a character who wants to start a nursery and even produce a new variety of rose.  Here are some general steps they would have to take.  By the way, I'm not going to cover activities such as getting enough land, having glass houses or cold frames erected, and obtaining some starting stock.

During the first two to three years, the character will be building up supplies of roses to be used as root stock.  These will generally be "common" roses such as the Dog Rose (Rosa Canina).

If they have already have two roses they wish to use for the pollen and seed parents, then they can also use these first years as follows:

------Year 1:  Pollinate the seed parent in the spring and in the fall, collect the seeds.  Plant the seeds.  Start reproducing your root stock (generally created by suckers and layering).

------Year 2:  In the spring, monitor the progress of the seedlings.  Snip off any buds so they do not bloom (we are talking rose buds as opposed to eyes or buds used for propagation).  You don't want them to waste growing energy by blooming.  Continue reproducing your root stock--you'll need it later.

------Year 3:  In the spring, monitor the progress of the one-year old plants.  Watch growth habits and allow them to bloom, noting bloom color, shape, texture, etc.  Ugly or poor-growing specimens should be eliminated.  The only exceptions would be plants with especially beautiful blooms which may not be as vigorous as the rest, but make up for lack of vigor in beauty and/or perfume.  You may be monitoring as many as 1,000 to 2,000 seedlings.  Continue reproducing your root stock.

--By year four, there should be sufficient root stock available to be used to start grafting the bud eyes from any roses you grew from seed, which were especially beautiful.  Name your new rose(s).  Keep in mind that names in this period were generally the names of your benefactors--don't make the mistake of using modern sounding rose names like Sexy Rexy or Hot Tamale.  Names then were generally either a benefactor, a member of the grower's family (e.g. Mme Hardy), or something poetic, e.g. (Great Maiden's Blush or The Apothecary's Rose).

----Year 4:  A single cane may provide 30 or so (depending upon the length and vigor of the cane) bud eyes.  You can remove all the bud eyes, and then remove the cane, from the original rose you wish to reproduce.  These bud eyes will be inoculated (that is the Regency term) or grafted onto the root stock and allowed to grow there, producing a new plant.  Depending upon the vigor of the original rose and how many canes it has, you may be able to produce a 100 or so new roses.  Remember, you MUST leave SOME canes for that original rose to continue to grow, so that you may continue to create new roses for your customers from it.  You will NEVER be able to "re-create" a rose raised from seed, by seed, for it will not breed true, so this one, original rose, will be the ONLY rose you have of that type, until you create more.

------Your stock to sell will most likely be created by inoculation.  You may also, depending on the rose, be able to obtain a few more by layering or suckers, but this would be five or six new plants (although they would have their own roots and would be good for building up your stock of original roses from which you can remove bud eyes in successive years, to inoculate and sell.)

--By year five, the inoculated plants may be large enough to sell, and you may have 100 or more plants.  You can see that after year five, you can produce many-fold more roses of the same type.  For example, you can produce 100 inoculated roses to sell, while increasing your original rose stock through layering and/or suckers in year 4, so that in year five, you may have 5 roses from which you can remove canes with bud eyes for inoculation.  So, by year 5, you may be able to inoculate 600 rose root stocks (100 from the original, and then 100 each from the 5 suckers or layered roses you created in year 4.)  You can also start removing bud eyes from grafted roses, and inoculating more root stock, to increase
production of saleable roses.

Important Note:  When a grower announces they have produced a new rose, it may be several years before it is widely available.  Keep this in mind when you look at the dates of introduction of rose varieties.  A rose introduced in 1810, may have begun life as a seedling in 1806, and there may be only 100 or so plants available the year of introduction.  (Which explains one of the articles I read where men actually had a fist-
fights during the auction of a new rose variety --I believe there were 60 roses of this new variety available.  The men ended up in a tug-of-war and pulled apart the last rose, and had to pay a fine for damages...)

A rose purchased in 1810 will grow the first year to a moderate
size, and larger in succeeding years, but may not attain true size/maturity for several years.  So, you won't have a truly large, magnificent rose specimen until around 1813 or so, from that rose started in 1806.  This is important in describing gardens, since it would be foolish to talk about a 30' specimen growing through a tree or over an arbor in 1812, that was introduced in 1810.  A rose introduced in 1810 would probably not be that large until at least 1814 and more likely, 1815 or 16.

SUCKERS
Some roses are more prone to suckering than others.  Gallica, or French, roses are very prone to suckering, so if your character creates new Gallica roses (a very popular class of rose during the Regency) they would have been likely to be able to produce more of the original, new rose, through suckering, to increase their breeding stock.

YELLOW ROSES
Forget them during the Regency.  Do NOT include them in your stories
until at least 1835 or later.  This bears repeating.  There were no yellow roses in England during the early years of the 19th century, that would look anything like a rose you are familiar with.  Your characters would not create one either because it wasn't until mid-century that hybridizers solved the breeding problem between European varieties of roses and China varieties to be able to introduce things like remontant roses and yellow roses...  This was strictly a scientific limitation based upon the chromosomes in the rose.

TERMS
Inoculation:  When you explain using bud eyes to graft onto root stock to create more roses, you should use the term inoculation for this process.  You will obviously have to figure out a way to explain it to your readers because they will think you are nuts to use this word.  You will have to decide how accurate you want to be.

French roses:  Until around 1814, the Gallica class of rose was often referred to as French roses.  Just keep this in mind.  The book, Les Roses, was one of the things that lead to the current class name of Gallica.

Provence roses:  Until around 1814, the Centifolia class of rose was often referred to as Provence roses.  Just keep this in mind.  The book, Les Roses, was one of the things that lead to the current class name of Centifolia.