Then in most of these habitats there will be some rain or snow in the spring. Then in spring the ground will be cool and very damp. Many seeds will germinate in early spring under cool damp conditions, after the needed freezing/thawing cycles of mid winter.
In the summer often it is dry, occasionally there will be thunderstorms. The ground will experience very high surface temperatures, be mostly dry, but occasionally very wet when thunderstorms come frequently in short bursts.
If you live where sharp frosts occur in the winter, try to sow the seeds by the end of January if possible, so that enough freezing/thawing cycles can occur.
seeds Pediocactus /4,6,9,18/ all small very cold hardy types PKT 100 #1147.85-despainii SB1014 Emory Co, Ut shiny white spines, peachy fl. 1.50z 12.00 #1148-knowltonii SB304 San Juan Co, NM, tiny stems, early pink fl 1.25z #1149.6-peeblesianus SB571 Navajo Co, AZ thick corky spines 1.50z 1157-simpsonii SB586 Wayne Co, UT dark grey spines, pink flowers 1.00z 8.00 1170-simpsonii v. minor SB930 Grand Co, COL pink flowers 1.00z 8.00 Sclerocactus /4,6,9,11,18/ colorful spiny plants, super flowers #1219.4-glaucus DJF1185.7 Mesa Co, COL low thick stem, pink flowers 1.00z 8.00 1219.75-cloveriae SB305 w Farmington NM freely flowers, small stem 1.00z 8.00 1219.82-cloveriae 'reevesii' SB746 se San Juan Co, NM larger stems 1.00z 8.00 1220.707-parviflorus DJF697 Duchesne Co, Ut black + white spines 1.00z 8.00 1221.3-parviflorus SB559 Shiprock NM big lavender flowers 1.00z 8.00 1226-parviflorus SB848 Mexican Hat, Ut, shiny yellow-brown spines 1.00z 1234-parviflorus 'intermedius' SB593 Mohave Co AZ nice golden sp 1.00z 8.00 #1239.4-pubispinus SB1085 Millard Co UT yellow flowers, 1.25z 9.00 1241-spinosior SB740 n Sevier Co UT ribbon-like curly spines 1.00z 8.00 1241.2-'busekii' = S sileri SB1086 Coconino Co, AZ unusual 1.50z 12.00 1243-whipplei SB472 Navajo Co AZ yellow flowers, flat white spines 1.00z 8.00 1243.5-whipplei SB735 Apache Co AZ TL pygmaeus, flat stem, papery sp 1.00z 8.00 #1244.5-wrightiae SB516 Wayne Co, UT tiny stem, super scented fl 1.25z 9.00 1244.55-'gradyi' = S cloveriae ssp brackii SB1011 San Juan Co NM 1.25z 9.00 1244.56-wetlandicus SB1323 Uintah Co UT robust white spines 1.50z 1244.58-brevispinus RP25 Duchesne Co UT very tiny spines 1.50z 12.00 Toumeya /4,6,9,18/ tiny thin erect stem, papery spines, white flowers #1280-papyracantha, hides in dry brown grass, brown papery spines 1.00z #1280.2-papyracantha RP50 Navajo Co AZ 1.25z 1280.4-papyrancantha RP91 Otero Co, NM with light pink flowrs 1.50z 9.00 #1283-papyracantha SB504 Bernalillo Co NM robust stems, can branch 1.25z #1283.02-papyracantha SB1326 Valencia Co NM dark brown spines 1.25zSummary of sowing method used here in New Mexico:
If long heavy rains are possible where you live, it would be best to put the pots under cover after some germination has taken place. The outdoor treatments are designed to accomplish germination. For example the plants do not like long soaking rains in late summer and into the fall, so you might have to move the pots to an unheated greenhouse or coldframe once they have sprouted. However a long soaking rain is very beneficial in promoting germination.
The easiest to sprout are: Pediocactus simpsonii, Sclerocactus spinosior, pubispinus, and brevispinus. They will often sprout in early spring when it still freezes a bit at night. They find early spring a very active growth time when it is cool and moist.