Some articles mention "zones". Where can I find out what they are?
The articles are referring to USDA hardiness zones and more information can be found here: https://planthardiness.ars.usda.gov/
Most of the UK falls into USDA zone 9. Here is more info:
https://www.gardeningknowhow.com/planting-zones/uk-hardiness-zones.htm
I am ordering bulbs and hope to have flowers by the first week in June. Am I ok getting ones that say "early to mid Spring? Or should I stick to late Spring, early summer?
Generally, I would stick to what the packaging says. Most plants are labeled, regionally, so they will be planted during approximate times.
I would follow the instructions for your area, and on the packaging, depending on the type of plant.
I am looking for colorful perennial flowering plants for a very foggy San Francisco. 94116-2408
You will be zone 10! Warmer climate plants will be necessary. Typically, your region will be lumped in with 9 and 11, as well.
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-9-10-11/plants-zones-9-11.htm
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-9-10-11
I’m planting a rose of Sharon I need to know what zone I’m in thank you
While using our site, you will need to use the USDA zone equivalency. Yours will be 5b in Canadian zones, which puts you at 4b in US zones. When using our site, you can plant anything that goes down to 4b, as we use the US system.
https://www.gardeningknowhow.com/planting-zones/are-canada-zones-similar-to-us.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rose-of-sharon
I live about an hour North of San Francisco. What zone am I in?
You are in U.S. Plant Hardiness Zone 9b (min temp 25 to 30 degrees F). We have several gardening articles divided by zones. Here is more info:
https://www.gardeningknowhow.com/planting-zones/what-do-hardiness-zones-mean.htm
https://planthardiness.ars.usda.gov/
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-9-10-11
Is it climate or geographically based or something else?
This will be geographically based.
https://www.gardeningknowhow.com/planting-zones/what-do-hardiness-zones-mean.htm
Really enjoyed the article on early seed planting. Does this work in all zones? I live in Montana, which is zone 4. Thanks
Here is a good article about seed starting in zone 4:
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-4/zone-4-seed-starting.htm
Is this the article you saw? It specifies what to do in cold and warm regions.
https://www.gardeningknowhow.com/garden-how-to/propagation/seeds/planting-seeds-in-fall.htm