one thought - you did not provide any tractor or engine numbers. the tractor battery may be completely shorted and there is not enough voltage for the anti after fire solenoid. This device is part of the carburetor. Fuel flow through the carburetor stops.

Hydrangeas are shrubs, not herbaceous perennials. And with the type of hydrangea illustrated in the photo - Hydrangea macrophylla - you do NOT want to be cutting back to the ground (or to any low set of buds) as that will effectively remove much (if not all) of the potential for next year's flowers. The vast majority of Hydrangea macrophyllas, aka bigleaf hydrangeas, bloom on growth that was produced the previous season. Latent flower buds are produced at the terminal ends of branches in later summer and early fall - they are present NOW and cutting back hard will remove them. The exceptions are some newer introductions that will also bloom on current season's growth as well, although that feature is usually iffy at best, except under nearly ideal growing conditions. Lack of flowering on these types of hydrangeas is nearly always due to cold damage to the flower buds and/or improper pruning techniques. Pruning should be kept to a minimum.......generally just deadheading old flowers immediately under the flowerhead or the removal of deadwood in spring after the plant has fully leafed out. Anything more than this will removal the shrub's ability to flower in the coming season. And if you are growing this plant in a zone lower than 7, winter protection for the shrub is highly recommended to avoid cold damage to the latent flower buds and subsequent lack of flowering next season. As to issues with this specific plant, it looks to be in pretty good shape in the OP photos. But depending on where you are located, it is very late in the season for these shrubs and they are starting to shut down and enter dormancy - yellowing, drying and spotting of leaves at this time of year is to be expected :-)) FWIW, there is a dedicated Hydrangea forum here at Garden Web, where you can post to get detailed and experienced info on growing these plants. Siting of the plants can be critical to maintaining good health (avoiding too much midday sun, for example, and reflected heat). The rock mulch would not be my first choice for these shrubs for several reasons.

The truth is that evergreen azaleas are not really suited for Z5 climates unless they are grown in very protected niches and/or given winter shelter from burlap or other barriers. Labels and catalog listings make claims to the contrary and hide behind the "semi evergreen" ruse, but they all wind up looking just like yours after a typical Z5 winter. Your theories are logical and might apply if you lived in a warmer place, but plain old cold temperatures and wind are to blame, nothing else. Any flower buds set last year were probably killed. If you prune back to live wood, new growth will very likely emerge, but next winter will result in the same sort of damage. You can try barriers of burlap or evergreen boughs to protect from sun and wind, but this doesn't really do anything to modify deep cold. There are rhododendrons and deciduous azaleas which will grow and flower well in Z5, but Karen and other evergreen azaleas just won't.

you need to learn how to insert finger and FIND OUT when your plants need water ... and/or when your soil needs water ... you have to learn how to NOT guess ... every 3 or 4 days.. may or may not be good enough ... and that is why relying on lawn sprinklers or some such.. often fails ... once you figure out how moisture moves thru your soil.. you might be able to use an automated system ... but then you will have the problem of some of the plants being too wet.. and others too dry ... so.. i suspect transplant shock.. related to less than stellar watering ...[you didnt really tell us when they were planted] but 2 thumbs up for noting the new growth is unaffected ... and .. to me.. that means you are close to getting it right .... if new growth was impacted.. you would be looking at serious problems ... btw .. once fully established ... once they have gotten over transplant shock.. you may have to adjust watering again ... ken