I use the cherry syrup on ice cream and it is heaven!
Potatoes. Rotate every year, if you have space. They would be best after a crop or two of sweet corn. Most other crops grown in the garden are alternate hosts for various potato pests. If you don't have space to rotate, don't sweat it, it's not like you are trying to grow them commercially. What varieties of potato are you growing? Not every variety will do well in all soil types/ environment.
Several that I grow:. Superior, a round white early season variety (90 day). Good for boiling, potato salad, etc. Won't store very long. Only needs about 100#/acre nitrogen. Good on most soil types, but like all potatoes, the looser the soil the better.
Norland, very similar to Superior, but red skinned. Similar characteristics. Supior and Norland are the potatoes I start digging as soon as they are golf ball sized for "new potatoes".
Yukon Gold, very popular since they have yellow flesh, but they can have more problems in the garden. They are very susceptible to scab, and they go off shape in heavier soils. Need around 150# nitrogen/acre. Don't store very long. Longer season potato compared to Superior.
Pontiac, red skinned potato, longer season than Norland and larger yielding. Short storage season. 150# nitrogen.
Kennebec, full season (120 day)oblong white skinned. Good storage potato. Grow these to use all winter long. 175# nitrogen.
Always buy certified seed potatoes. Trying to save them from year to year only increases virus load in the potatoes. Don't ever use potatoes bought at the grocery store for planting. They all have sprout inhibitor sprayed on them, and even though they may grow, they will not produce a normal crop.
Tip:150 # nitrogen per acre equals 25 oz of 13-13-13 fertilizer per 20 ft of row.
I use a systemic insecticide at planting, followed by foliar sprays later in the season for leafhoppers. Colorado potato beetle and leafhoppers are going to do the most damage to potatoes.
For disease, I use Daconil (chlorothalonil) and start spraying when the potatoes start filling in between rows.
Most important with potatoes is getting enough nitrogen on them. I till in nitrogen before planting. You don't necessarily need to apply fungicide, but it can help in raising final yield. Consistent moisture (rain or watering) is also important.
Garlic. I plant anywhere from late October to mid November, just want them in the ground before it freezes. You can plant in the spring but will have much smaller yield. Hard neck varieties are the best in our area. Several of my favorite varieties are "Armenian", "Romanian", "Chesnok Red" and "Spanish Roja".
BTW, if you have a hard time finding potato seed, try Jung Seed in Wisconsin. They carry many varieties, and might even have some garlic cloves for sale in the spring. I bought my garlic from a producer out west several years ago, and plant the largest cloves I produce each year. Garlic can be planted from year to year with saved cloves.