It's all about timing of the flowers (OK, mostly about timing, there are some types that don't pollinate others). Overlap your bloom periods and you are generally set for pollination.
FYI, I am talking about bloom period not ripening date.

Once you have more than 2 varieties you generally end up fine unless you happen to get all in the same period.

Out of what you got so far Paulared is early. Honeycrisp is a mid/late. Sweet 16 is late. Snowsweet is mid/late.

You may throw in another early to make sure the Paulared has something should it decide to go extra early. Another late would ensure the Sweet 16 has something should frost or warm weather knock the earlier ones down.
Long bloomers also help ensure you always have bloom periods overlapping.
But in most years you would probably be set as it is.
Goldrush is a mid-late bloomer and a lot of people like it here. Braeburn is an early-mid bloomer and IMO you can't go wrong with tried and true. Crabapples tend to be good because they bloom long.

Distance is line of sight for the bugs doing the pollinating and their willingness to travel for food. If you have a mass of Honeycrisp and Snowsweet blooming at one time and one Paulared with the blooms on their last legs 100yds away they may not bother with the Paulared. But if you have the only two flowers in a mile radius the same pollinator may visit both because it's all they have.
If you're setting up an orchard it shouldn't be an issue.

Bee hives give you control over that aspect. If disease wipes out your hive you know to replace them. You can set your hive in a spot that it warms up with your blooms so the bees are out when the flowers are open. But it's not required.

Thx for response. I will add an "early" as you suggest. I didn't mention I also have "state Fair" which is a late so I should be good there.

No I just have to figure out what Cherry tree variants I want to plant.

Almost all commercial apple growers now rely on crab apples. they produces 3-4 x as much pollen and take up little room in the Orchard. Unless you plan to save seed and grow new apple tree hybrids, I'd get a cold hardy Crabapple.... and get several varieties to stagger the bloom period, an early bloomer, a midseason bloom and a late bloomer.

Here is a link that might be useful: Hardy Crab Apples

Charts are regionally specific and the further south you go the wider the time frame between early and late flowering varieties. Where I am, home orchards require very little consideration of timing as early and late usually have enough overlap to pollenize one-another. Further south, I am repeatedly told, this is not the case and earliest flowering varieties have long since lost there petals when the lates first open on most seasons.

I install orchards professionally and the only thing I consider when matching varieties for pollenation is being aware of triploids, which are virtually pollen sterile.

Washington state lists bloom data for many apples.

If you're still uncertain, The Home Orchard Society sells an eBook that groups over 1000 apple varieties into 4 pollination groups, and specifies which varieties are triploid. It's $10.

Hope that helps!

I like to use Keeper's in the UK to check for which bloom times overlap for most fruit trees (apple, cherry, plum, etc.--not so much apricots!) They have them listed by days from the first variety to bloom, and in groups to cross pollinize (A, B, C, etc.) I'm sure the actual date will be different for most of us, but they are the BEST for checking out varieties, especially heirloom varieties. Be sure to check out all the links on the left for each variety, often they have a photo and characteristics.

If only they shipped to California... :(

Carla in Sac

Here is a link that might be useful: Keepers' master list of fruit trees by name

I bought a Honeycrisp tree and then realized I knew nothing when my 7th grade son said, what are you going to do about cross pollination. I went back to the nursery and they recommended a Zestar for my second tree. I am a little concerned that they weren't sure what they were talking about. Will a Zestar cross pollinate a Honeycrisp? I live in Northern Illinois.

Depending on where you live, your neighborhood may have crab apples around to help in the pollination dept. I know my neighborhood has them all over.

I just planted a Braeburn today. I am looking to plant a Honeycrisp 20 feet from it. Will these two pollinate one another well? I don't have a large yard so I don't really want to plant a crabapple too. Thank you.

Will Braeburn ripen properly in Minnesota? I'm in Z6 and it just makes it here.

I have read that if you go with a flowering crab, select one with the same colored blooms as your apples as the pollinators work similar colored blooms. Maybe that is an old wives tale, beats me.

Mark,

I saw in this thread that 'myk1' recommended the tried and true 'Braeburn Apple' to you. While they do produce good fruit and may be tried and true in the region where he lives it won't work in central MN.

Many have tried unsuccessfully to grow it here- in MN the tree isn't cold hardy enough, but the main issue will be ripening too late. It would surprise me if you ever taste a ripe apple from a MN grown Braeburn (if one lives long enough to bare).

Sticking with the University of Minnesota apple varieties is the way to go. If the commonly found commercial apple varieties worked in MN the University wouldn't have started the breeding program 150 years ago in the first place.

From (http://www.minnesotaharvest.net/apple_wealthy.htm) "The Wealthy Apple: Starting from Seed"

In 1860, Horace Greeley told his audience, "Never move to Minnesota...you can't grow apples there!" This was the same Horace Greeley who was responsible for the grand command of the century, "Go West, Young Man!" For Minnesota, a pioneer land only two years into statehood, such a reputation was sure to be detrimental to efforts aimed at attracting westward-moving Easterners to settle here.

His apple statement was true at the time. But even as Greeley spoke, a fruit-loving Minnesotan was planting and evaluating apple trees started with seeds collected from northern sources, even some from Siberia.

As a MN fruit grower I would recommend that you get at least one Zestar tree. It is the offspring of State Fair, and shares its early September ripening date. Zestar is a large firm apple with a great sweet and tart flavor perfect for fresh eating or cooking. Other good UMN varieties include (honeygold, haralson, wealthy, macintosh, chestnut crab, regent, connel red...)

With the number of varieties you have planted, you shouldn't have any trouble with pollination. If you do find that your early or late season bloomers aren't setting good crops flowering crab apples make the best pollinators. Crabs are best because they are selected for their extended bloom period and profusion of flowers (more flowers=more pollen). Make sure you choose an ornamental crab that sets fruit, the fruitless ones are sterile and won't produce viable pollen.

Here is a fact sheet from the U of Wisc. on crabapples if you decide to go that route.

Here is a link that might be useful: Crabs fact sheet