Gardeners are always wanting to learn more about growing,and the techniques used by commercial growers. Contact the growers in your area and see if they are interested in (for the publicity value)speaking to the meeting about the latest thing used in their growing program. Al

Simple landscaping projects.

If lawns and grass-growing are big in your area - anything that will help solve the local problems - weeds, critters, feeding, grass varieties.

Pruning - particularly roses and hydrangeas and monster trees. Plus how to deal with trees too close to the power lines, the house, the neighbour when you aren't an arborist.

Getting rid of the locally important pest plants (or at least keeping them in some sort of order...eg english ivy, and japanese knotweed and... name your plague.)

And, as Al says - how to get magnificent displays like the professionals. Soil prep. Feeding. Timing. Watering. Plant material. Plant combinations.

For the non-mainstream - baskets and container gardening, flowers, bulbs, architectural plants, and veggies, and growing/using natives, single-colour and textured gardens, gardens for people with allergies or disability and creaky knees - converting a garden for these reasons. Organics and permaculture, if you think there are enough 'aged hippies' who would come along ;-)) Plus gardens for improving aesthetics and street appeal/property value.

Oh, and overwintering of treasures and outside the grow zone specimens.

Some outside-the-box speakers our local group had, that were very interesting: a florist known for his creativity, a birdwatcher, a park naturalist, a beekeeper, and someone that "salvaged" native plants from impending road construction.

We have a county jail with a horticulture program for inmates. The director of that program is in demand for speaking to gardeners about how well working in the garden has a pacification effect. Of course some of them are in the jail for their successful gardening of prohibited plants. Al

LOL!

We recently had a talk on fire-wise landscaping. If you are in an area prone to brush or forest fires, this could be of real benefit to the MGs and property owners. Your state forestry service should have information and perhaps a speaker.

We also have talks on pollinators, small-space vegetable gardening, organic vegetable gardening, irrigating the home garden, rain barrels, composting, lawn care (spring, summer, and fall sessions), and preparing the garden for winter. Of course, there are always talks on the more common subjects such as insects and plant diseases and such.

Good luck with your new responsibility.

Sandy

We've had good luck finding topics from within the group. Some past programs are "bring your favorite gardening tool and tell us why you like it", "bring a weed/insect/plant problem for ID/control measures", a gardening hat contest, favorite gardening books/websites, bring a snack/food item from your garden, garden photo exhibit, favorite garden accessory/junk/repurposed item and holiday deco's from your yard. I really like these because they aren't passive, sit in your chair and be assailed by words meetings. You also get to know your fellow MG's more.
Of course not everyone plays along but that's normal. There are folks out there who sit and let others do all the work...even in MG units.
Good luck!

A few that I have used over the years:

Accessable gardening (gardening with disabilities/aging)
Invasive species (There is always something new on the horizon)
A primer on plant breeding/genetic engineering
Had a pro flower show judge show the tricks of the trade

Propagation. How, when and what depending on the plant and the time of the year. Our MG teacher (hort. agent) gave us a sheet with lots of good info on it.(Florida) Most cuttings were 4-6 inches long. I have good luck with 8-12 inch cuttings. I love to experiment with propagating at the wrong times and with longer cuttings. Sometimes it works. Air layering, rooting African violets in soil and water. Using rootone and dip hormones versus not using them. I prefer not to. I have pretty good luck without them. We were asked to bring in cuttings (in water) to exchange with others to root. It was a fun way to learn and get new plants. I always go by the book when I am asked a question at the master gardener office. I jsut like to experiment when I can.

I'm in the same situation trying to come up with ideas! Some of my favorites that we've had lately were on drip irrigation, monarch butterflies, and decorating for the holidays with things from your yard. We have also done some garden tours that were pretty neat--a daylily farm/expert, a vineyard/winery, and tours of the members gardens.