Parsnips are just now coming into their own with no need to worry about rushing to harvest before frost. In fact freezing actually improves root quality so bring on the cold weather. Roots can be dug as needed or stored moist (vented plastic bags) in the refigerator for a couple weeks so starches are converted to sugar for roots to have a better flavor.
Parsnips are grown from seed planted in early spring (April). 'Harris Model' and 'All American' are two standard varieties but most should grow well here. Fresh seed is a must as old seed germinates poorly. Like their parsley family cousin, carrots, seed takes 2 to 3 weeks to germinate. Seed is often over-planted because of poor germination and then seedlings thinned to 4-6 inches between plants.
This is a full season crop averaging 110 to 120 days (4 months) to mature. A deep, loose soil is a must just like carrots. Once top foliage grows to cover over, most weeds should cease being a problem. Supply steady moisture to avoid root disorders but note overwatering can cause forking and hairy roots. Moisture fluctuations produce cracking. Organic mulches (grass clippings or straw) in summer are helpful for weed and moisture control.
Parsnips are a different root vegetable to try for a variation from carrots and beets.
Photo credit: Parsnips in raised bed, harvested parsnip roots - both Carl Wilson